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Not to be confused with full genome sequencing.
DNA profiling (also called DNA testing, DNA typing, or genetic fingerprinting) is a technique employed by forensic scientists to assist in the identification of individuals on the basis of their respective DNA profiles. DNA profiles are encrypted sets of numbers that reflect a person's DNA makeup, which can also be used as the person's identifier. DNA profiling should not be confused with full genome sequencing.[1] It is used in, for example, parental testing and rape investigation. Although 99.9% of human DNA sequences are the same in every person, enough of the DNA is different to distinguish one individual from another.[2] DNA profiling uses repetitive ("repeat") sequences that are highly variable,[2] called variable number tandem repeats (VNTR). VNTRs loci are very similar between closely related humans, but so variable that unrelated individuals are extremely unlikely to have the same VNTRs. The DNA profiling technique was first reported in 1984[3] by Sir Alec Jeffreys at the University of Leicester in England,[4] and is now the basis of several national DNA databases. Dr. Alec Jeffreys genetic fingerprinting was made commercially available in 1987, when a chemical company, ICI, started a blood-testing center in England.[5]
[edit] DNA profiling processThe process begins with a sample of an individual's DNA (typically called a "reference sample"). The most desirable method of collecting a reference sample is the use of a buccal swab, as this reduces the possibility of contamination. When this is not available (eg because a court order may be needed and not obtainable) other methods may need to be used to collect a sample of blood, saliva, semen, or other appropriate fluid or tissue from personal items (e.g. toothbrush, razor, etc) or from stored samples (e.g. banked sperm or biopsy tissue). Samples obtained from blood relatives (biological relative) can provide an indication of an individual's profile, as could human remains which had been previously profiled. A reference sample is then analyzed to create the individual's DNA profile using one of a number of techniques, discussed below. The DNA profile is then compared against another sample to determine whether there is a genetic match. [edit] RFLP analysisMain article: Restriction fragment length polymorphism The first methods for finding out genetics used for DNA profiling involved restriction enzyme digestion, followed by Southern blot analysis. Although polymorphisms can exist in the restriction enzyme cleavage sites, more commonly the enzymes and DNA probes were used to analyze VNTR loci. However, the Southern blot technique is laborious, and requires large amounts of undegraded sample DNA. Also, Karl Brown's original technique looked at many minisatellite loci at the same time, increasing the observed variability, but making it hard to discern individual alleles (and thereby precluding parental testing). These early techniques have been supplanted by PCR-based assays. [edit] PCR analysisMain article: polymerase chain reaction With the invention of the polymerase chain reaction (PCR) technique, DNA profiling took huge strides forward in both discriminating power and the ability to recover information from very small (or degraded) starting samples. PCR greatly amplifies the amounts of a specific region of DNA, using oligonucleotide primers and a thermostable DNA polymerase. Early assays such as the HLA-DQ alpha reverse dot blot strips grew to be very popular due to their ease of use, and the speed with which a result could be obtained. However they were not as discriminating as RFLP. It was also difficult to determine a DNA profile for mixed samples, such as a vaginal swab from a sexual assault victim. Fortunately, the PCR method is readily adaptable for analyzing VNTR loci. In the United States the FBI has standardized a set of 13 VNTR assays for DNA typing, and has organized the CODIS database for forensic identification in criminal cases. Similar assays and databases have been set up in other countries. Also, commercial kits are available that analyze single nucleotide polymorphisms (SNPs). These kits use PCR to amplify specific regions with known variations and hybridize them to probes anchored on cards, which results in a colored spot corresponding to the particular sequence variation. [edit] STR analysisMain article: Short tandem repeats The method of DNA profiling used today is based on PCR and uses short tandem repeats (STR). This method uses highly polymorphic regions that have short repeated sequences of DNA (the most common is 4 bases repeated, but there are other lengths in use, including 3 and 5 bases). Because different unrelated people have different numbers of repeat units, these regions of DNA can be used to discriminate between unrelated individuals. These STR loci (locations) are targeted with sequence-specific primers and are amplified using PCR. The DNA fragments that result are then separated and detected using electrophoresis. There are two common methods of separation and detection, capillary electrophoresis (CE) and gel electrophoresis. The polymorphisms displayed at each STR region are by themselves very common, typically each polymorphism will be shared by around 5 - 20% of individuals. When looking at multiple loci, it is the unique combination of these polymorphisms to an individual that makes this method discriminating as an identification tool. The more STR regions that are tested in an individual the more discriminating the test becomes. From country to country, different STR-based DNA-profiling systems are in use. In North America systems which amplify the CODIS 13 core loci are almost universal, while in the UK the SGM+ system, which is compatible with The National DNA Database, is in use. Whichever system is used, many of the STR regions under test are the same. These DNA-profiling systems are based around multiplex reactions, whereby many STR regions will be under test at the same time. The true power of STR analysis is in its statistical power of discrimination. Because the 13 loci that are currently used for discrimination in CODIS are independently assorted (having a certain number of repeats at one locus doesn't change the likelihood of having any number of repeats at any other locus), the product rule for probabilities can be applied. This means that if someone has the DNA type of ABC, where the three loci were independent , we can say that the probability of having that DNA type is the probability of having type A times the probability of having type B times the probability of having type C. This has resulted in the ability to generate match probabilities of 1 in a quintillion (1 with 18 zeros after it) or more. However, since there are about 12 million monozygotic twins on Earth, that theoretical probablitity is useless. For example, the actual probability that 2 random persons have the same DNA is only 1 in 3 trillion. [edit] AmpFLPMain article: Amplified fragment length polymorphism Another technique, AmpFLP, or amplified fragment length polymorphism was also put into practice during the early 1990s. This technique was also faster than RFLP analysis and used PCR to amplify DNA samples. It relied on variable number tandem repeat (VNTR) polymorphisms to distinguish various alleles, which were separated on a polyacrylamide gel using an allelic ladder (as opposed to a molecular weight ladder). Bands could be visualized by silver staining the gel. One popular locus for fingerprinting was the D1S80 locus. As with all PCR based methods, highly degraded DNA or very small amounts of DNA may cause allelic dropout (causing a mistake in thinking a heterozygote is a homozygote) or other stochastic effects. In addition, because the analysis is done on a gel, very high number repeats may bunch together at the top of the gel, making it difficult to resolve. AmpFLP analysis can be highly automated, and allows for easy creation of phylogenetic trees based on comparing individual samples of DNA. Due to its relatively low cost and ease of set-up and operation, AmpFLP remains popular in lower income countries. [edit] Y-chromosome analysisRecent innovations have included the creation of primers targeting polymorphic regions on the Y-chromosome (Y-STR), which allows resolution of a mixed DNA sample from a male and female and/or cases in which a differential extraction is not possible. Y-chromosomes are paternally inherited, so Y-STR analysis can help in the identification of paternally related males. Y-STR analysis was performed in the Sally Hemings controversy to determine if Thomas Jefferson had sired a son with one of his slaves. [edit] Mitochondrial analysisMain article: Mitochondrial DNA For highly degraded samples, it is sometimes impossible to get a complete profile of the 13 CODIS STRs. In these situations, mitochondrial DNA (mtDNA) is sometimes typed due to there being many copies of mtDNA in a cell, while there may only be 1-2 copies of the nuclear DNA. Forensic scientists amplify the HV1 and HV2 regions of the mtDNA, then sequence each region and compare single nucleotide differences to a reference. Because mtDNA is maternally inherited, directly linked maternal relatives can be used as match references, such as one's maternal grandmother's daughter's son. A difference of two or more nucleotides is generally considered to be an exclusion. Heteroplasmy and poly-C differences may throw off straight sequence comparisons, so some expertise on the part of the analyst is required. mtDNA is useful in determining clear identities, such as those of missing persons when a maternally linked relative can be found. mtDNA testing was used in determining that Anna Anderson was not the Russian princess she had claimed to be, Anastasia Romanov. mtDNA can be obtained from such material as hair shafts and old bones/teeth.. [edit] DNA databasesMain article: National DNA database There are now several DNA databases in existence around the world. Some are private, but most of the largest databases are government controlled. The United States maintains the largest DNA database, with the Combined DNA Index System, holding over 5 million records as of 2007[6]. The United Kingdom maintains the National DNA Database (NDNAD), which is of similar size, despite the UK's smaller population. The size of this database, and its rate of growth, is giving concern to civil liberties groups in the UK, where police have wide-ranging powers to take samples and retain them even in the event of acquittal.[7] The U.S. Patriot Act of the United States provides a means for the U.S. government to get DNA samples from other countries if they[clarification needed] are either a division of, or head office of, a company operating in the U.S. Under the act, the American offices of the company can't divulge to their subsidiaries/offices in other countries the reasons that these DNA samples are sought or by whom.[citation needed] When a match is made from a National DNA Databank to link a crime scene to an offender who has provided a DNA Sample to a databank that link is often referred to as a cold hit. A cold hit is of value in referring the police agency to a specific suspect but is of less evidential value than a DNA match made from outside the DNA Databank.[8]. [edit] Considerations when evaluating DNA evidenceIn the early days of the use of genetic fingerprinting as criminal evidence, juries were often swayed by spurious statistical arguments by defense lawyers along these lines: given a match that had a 1 in 5 million probability of occurring by chance, the lawyer would argue that this meant that in a country of say 60 million people there were 12 people who would also match the profile. This was then translated to a 1 in 12 chance of the suspect being the guilty one. This argument is not sound unless the suspect was drawn at random from the population of the country. In fact, a jury should consider how likely it is that an individual matching the genetic profile would also have been a suspect in the case for other reasons. Another spurious statistical argument is based on the false assumption that a 1 in 5 million probability of a match automatically translates into a 1 in 5 million probability of innocence and is known as the prosecutor's fallacy. When using RFLP, the theoretical risk of a coincidental match is 1 in 100 billion (100,000,000,000), although the practical risk is actually 1 in 1000 because monozygotic twins are 0.2% of the human population. Moreover, the rate of laboratory error is almost certainly higher than this, and often actual laboratory procedures do not reflect the theory under which the coincidence probabilities were computed. For example, the coincidence probabilities may be calculated based on the probabilities that markers in two samples have bands in precisely the same location, but a laboratory worker may conclude that similar—but not precisely identical—band patterns result from identical genetic samples with some imperfection in the agarose gel. However, in this case, the laboratory worker increases the coincidence risk by expanding the criteria for declaring a match. Recent studies have quoted relatively high error rates which may be cause for concern[9]. In the early days of genetic fingerprinting, the necessary population data to accurately compute a match probability was sometimes unavailable. Between 1992 and 1996, arbitrary low ceilings were controversially put on match probabilities used in RFLP analysis rather than the higher theoretically computed ones [10]. Today, RFLP has become widely disused due to the advent of more discriminating, sensitive and easier technologies. STRs do not suffer from such subjectivity and provide similar power of discrimination (1 in 10^13 for unrelated individuals if using a full SGM+ profile) It should be noted that figures of this magnitude are not considered to be statistically supportable by scientists in the UK, for unrelated individuals with full matching DNA profiles a match probability of 1 in a billion (one thousand million) is considered statistically supportable (Since 1998 the DNA profiling system supported by The National DNA Database in the UK is the SGM+ DNA profiling system which includes 10 STR regions and a sex indicating test. However, with any DNA technique, the cautious juror should not convict on genetic fingerprint evidence alone if other factors raise doubt. Contamination with other evidence (secondary transfer) is a key source of incorrect DNA profiles and raising doubts as to whether a sample has been adulterated is a favorite defense technique. More rarely, Chimerism is one such instance where the lack of a genetic match may unfairly exclude a suspect. [edit] Evidence of genetic relationshipIt's also possible to use DNA profiling as evidence of genetic relationship, but testing that shows no relationship isn't absolutely certain. While almost all individuals have a single and distinct set of genes, rare individuals, known as "chimeras", have at least two different sets of genes. There have been several cases of DNA profiling that falsely "proved" that a mother was unrelated to her children.[11] [edit] Fake DNA evidenceThe value of DNA evidence has to be seen in light of recent cases where criminals planted fake DNA samples at crime scenes. In one case, a criminal even planted fake DNA evidence in his own body: Dr. John Schneeberger raped one of his sedated patients in 1992 and left semen on her underwear. Police drew what they believed to be Schneeberger's blood and compared its DNA against the crime scene semen DNA on three occasions, never showing a match. It turned out that he had surgically inserted a Penrose drain into his arm and filled it with foreign blood and anticoagulants. In a study conducted by the life science company Nucleix and published in the journal Forensic Science International, scientists found that an In vitro synthesized sample of DNA matching any desired genetic profile can be constructed using standard molecular biology techniques without obtaining any actual tissue from that person. Current forensic procedures are unable to distinguish between artificial and natural DNA. Dan Frumkin, lead author of the study said "You can just engineer a crime scene... any biology undergraduate could perform this." A very similar line was spoken by a geneticist who helped frame Olivia Benson on Law and Order: SVU Season 11 when he said, "It's so easy. Any biology undergraduate can do it." An authentication test is being developed.[12] [edit] DNA evidence as evidence in criminal trials[edit] Familial searchingFamilial searching is the use of family members' DNA to identify a closely related suspect in jurisdictions where large DNA databases exist, but no exact match has been found. The first successful use of the practice was in a UK case where a man was convicted of manslaughter when he threw a brick stained with his own blood into a moving car. Police could not get an exact match to the UK's DNA database because the man had no criminal convictions, but police implicated him using a close relative's DNA.[13] [edit] Surreptitious DNA collectingPolice forces may collect DNA samples without the suspects' knowledge, and use it as evidence. Legality of this mode of proceeding has been questioned in Australia. In the United States, it has been accepted, courts often claiming that there was no expectation of privacy, citing California v. Greenwood (1985), during which the Supreme Court held that the Fourth Amendment does not prohibit the warrantless search and seizure of garbage left for collection outside the curtilage of a home. Critics of this practice underline the fact that this analogy ignores that "most people have no idea that they risk surrendering their genetic identity to the police by, for instance, failing to destroy a used coffee cup. Moreover, even if they do realize it, there is no way to avoid abandoning one’s DNA in public." [14] In the UK, the Human Tissue Act of 2004 prohibited private individuals from covertly collecting biological samples (hair, fingernails, etc.) for DNA analysis, but excluded medical and criminal investigations from the offense. [15] [edit] England and WalesEvidence from an expert who has compared DNA samples must be accompanied by evidence as to the sources of the samples and the procedures for obtaining the DNA profiles.[16] The judge must ensure that the jury must understand the significance of DNA matches and mismatches in the profiles. The judge must also ensure that the jury does not confuse the 'match probability' (the probability that a person that is chosen at random has a matching DNA profile to the sample from the scene) with the 'likelihood ratio' (the probability that a person with matching DNA committed the crime). In R v. Doheny, EWCA Crim 728 (1996). Phillips LJ gave this example of a summing up, which should be carefully tailored to the particular facts in each case:
Juries should weigh up conflicting and corroborative evidence, using their own common sense and not by using mathematical formulae, such as Bayes' theorem, so as to avoid "confusion, misunderstanding and misjudgment".[17] [edit] Presentation and evaluation of evidence of partial or incomplete DNA profilesR v Bates (2006) EWCA Crim 1395 Moore-Bick LJ said:
[edit] DNA testing in the USThere are state laws on DNA profiling in all 50 states of the United States. These are the first DNA cases on record in each state.[19] Detailed information on database laws in each state can be found at the National Conference of State Legislatures website.[20] Alabama First Case: People v. Perry, guilty of rape, Scottsboro, 1988 Appellate Decision: Accepted DNA, remanded Perry to trial court on basis of statistics and three-pronged Frye standard, 1991; trial court found general acceptance of statistical analysis, 1992. Data Bank established:1994 Legislated Admissibility passed: 1994 Alaska First Case: DNA evidence accepted in criminal trial in Kodiak, 1990. Arizona First case: People v. Bible, Superior Court judge ruled to allow the introduction of DNA evidence in the murder trial of Richard Bible. Bible was charged with murder, kidnapping, and child molestation in the disappearance and death of a 9-year-old girl. Coconino County, 1989. Appellate Decision: People v. Bible, 1993. DNA evidence admitted, but statistical estimates excluded. Arkansas DNA evidence was admitted in a Little Rock rape case following a pretrial hearing in November 1989. Appellate Decision: Prater v. Arkansas, 1991. Affirmed DNA admissibility. California First case: People v. Axell, guilty of murder, Ventura County Superior Court, 1989. Appellate Decision: People v. Soto, 1994. Affirmed admissiom of evidence and statistics. Data Bank established: 1990 Colorado First case: People v. Gallagher, guilty of sexual assault, El Paso County, 1988. Appellate Decision: Fishback v. State of Colorado, 1993. Admitted DNA evidence and left statistical frequency questions to trial courts. Data Bank established: 1990 Connecticut First case: People v. Williams, PCR test conducted fails to show link between defendant and woman stabbed to death in a shopping center parking lot, Stamford, 1989. Appellate Decision: State v. Silvri, 1994. Judgment reversed and case remanded with recommendation to conform with NRC report. Data Bank established: 1994 Legislated Admissibility passed: 1994 Delaware First case: People v. Pennell, guilty of murder, Wilmington, 1989. Data Bank established: 1994 Legislated Admissibility passed: 1994 District of Columbia First case: Green v. District of Columbia, After being convicted in June, 1989, Green pursued DNA testing, which revealed that he was not the individual whose semen had stained the victim's clothing. Rape, kidnapping, and sodomy charges dropped in 1990 Appellate Decision: U.S. v. Porter, 1994. Affirmed admissibility and use of ceiling principle. Florida First case: People v. Andrews, guilty of rape, 1987. Appellate Decision: Toranzo v. Florida, 1992. Affirmed admissibility and frequency estimate. Data Bank established: 1990 Georgia First case: People v. Redding, DNA evidence admitted after pretrial hearing in rape case. Defendant pleaded guilty. Decatur, 1988. Appellate Decision: Morris v. State, 1994. Affirmed use of evidence and statistics. Data Bank established: 1992 Hawaii First case: People v. Manning, guilty of assault and burglary, Wailuku, 1989. Appellate Decision: State v. Montalbo, 1992. Admitted DNA evidence and found objections regarding statistical calculations go to weight rather than admissibility. Data Bank established: 1992 Idaho First case: People v. Horsley, guilty of rape, Sandpoint, 1988. Illinois First case: Case of Gary Dotson. Cook County judge vacates 1979 rape conviction after DNA test exculpates defendant. Dotson had been convicted in a 1977 rape, for which he spent 6 years in jail. Alleged victim recanted story in 1985, and Governor James Thompson granted clemency, but rape conviction remained on his record. Dotson had requested that the case be reopened for new trial after PCR tests excluded him. Cook County, 1989. Appellate Decision: People v. Lipscomb, 1991. Accepted DNA tests and statistical calculations. Data Bank established: 1990 Indiana First case: People v. Hopkins, guilty of rape/sodomy/ murder, Fort Wayne, 1989. Appellate Decision: McElroy v. State, 1992. Court upheld DNA admissibility and frequency calculations. Data Bank established: 1990 Legislated Admissibility passed: 1991 Iowa First case: People v. Vargason, guilty of sexual abuse, Johnson County, 1989. Appellate Decision: State v. Ripperger, 1994. Affirmed use of evidence and statistics. Data Bank established: 1990 Kansas First case: People v. Pioletti, guilty of murder, Wichita, 1988. Appellate Decision: State v. Wilson, 1991. Ruled that procedural questions related to weight of evidence rather than admissibility. Data Bank established: 1991 Kentucky Appellate Decision: Harris v. Commonwealth, 1992. Affirmed the use of DNA evidence and statistics. Data Bank established: 1992 Louisiana First case: People v. Quatrevingt, guilty of murder/rape, New Orleans, 1990. Appellate Decision: State v. Quatrevingt, 1992. Ruled DNA evidence is pro se admissible under Louisiana statute. Legislated Admissibility passed: 1990 Maine First case: People v. McLeod. The prosecution, in sexual molestation case, withdrew DNA evidence during a preliminary hearing on the reliability of the data, Portland, 1989. Maryland First case: People v. Tasker. Defendant pleads guilty to second-degree rape and draws 5-year prison sentence in case where DNA evidence introduced. Anne Arundel County, 1988. Data Bank established: 1994 Legislated Admissibility passed: 1991 Massachusetts First case: People v. Curnin, guilty of rape, Worcester, 1989. Appellate Decision: Commonwealth v. Daggett, 1993. The supreme court, unable to reach consensus on the admissibility of DNA evidence, ruled that even if the evidence was erroneously admitted, it was a harmless error. Michigan First case: People v. Fagan, guilty of rape, Flint, 1988. Data Bank established: 1994 Minnesota First case: People v. Nielson, guilty of murder, Ramsey County, 1989. Appellate Decision: State v. Johnson, 1993. Upheld admissibility of DNA evidence including frequency statistics for each individual locus and not the product of all loci. Data Bank established: 1990 Legislated Admissibility passed: 1989 Mississippi First case: People v. Weaver, guilty of rape, Hinds County, 1989. Appellate Decision: Polk v. State, 1992. Court found 3-prong Frye standard satisfied and evidence properly admitted. Data Bank established: from and after January 6, 1996. Missouri First case: People v. Thomas, guilty of rape, St. Louis, 1989. Data Bank established: 1990 Montana First case: People v. Drummond. Sexual intercourse without consent allegedly committed by a State institution attendant against a developmentally disabled patient. The victim gave birth and DNA comparisons were done by Lifecodes. Defendant pleaded guilty. Jefferson County, 1989. Nevada Data Bank established: 1990 Legislated Admissibility passed: 1989 New Hampshire First case: People v. Barnaby. DNA analysis admitted, according to State Attorney General's Office. Hillsborough County, 1989. Appellate Decision: State v. Vandebogart, 1992. Reversed admission of DNA evidence and remanded case to trial court to determine if ceiling principle was acceptable, which the trial court did. New Jersey First case: People v. Beard. Nearly 3 months after being charged with murder, the defendant was released after a judge ruled that authorities arrested the wrong man. The primary suspect in a 1975 Georgia murder disappeared after the crime. Mistakenly, his cousin (the defendant in this case) was arrested. DNA tests conducted by Lifecodes proved the jailed man was not the father of a man known to be the son of the suspect. Union County, 1989. Appellate Decision: State v. Williams, 1991. Affirmed the use of PCR. Data Bank established: 1994 New Mexico First case: People v. Collins. A man once charged with killing his stepdaughter was released from prison in October 1989 pending the outcome of DNA testing. Open murder charges against the defendant were dismissed in the interim. Santa Fe, 1989. Appellate Decision: State v. Anderson, 1994. Reversed Court of Appeals ruling that DNA evidence, admitted by trial court, was inadmissible due to statistical methodology. New York First case: People v. Zambrana, guilty of murder, New City, 1987. Appellate Decision: People v. Wesley, 1994. Affirmed admissibility and statistical estimates. Data Bank established: 1994 North Carolina First case: People v. Mills, guilty of murder, Salisbury, 1989. Appellate Decision: State v. Pennington, 1990. Affirmed use of DNA evidence and statistics. Data Bank established: 1993 North Dakota Ohio First case: People v. Dascenzo, guilty of aggravated murder, Montgomery County, 1988. Appellate Decision: Ohio v. Penton, 1993. Affirmed PCR and reiterated relevancy as admissibility standard rather than Frye standard. Oklahoma First case: People v. Hunt, first time Lifecodes testifies regarding DNA evidence in criminal case, defendant acquitted of murder, Norman, 1987. Data Bank established: 1991 Oregon First case: People v. Futch, DNA test results offered for admission at 7-month pretrial hearing, Clatsop County, 1989. Appellate Decision: State v. Lyons, 1993. Affirmed use of DNA evidence and statistics. Data Bank established: 1991 Pennsylvania First case: People v. Trubia, guilty of murder/rape, Lackawanna County, 1988. Appellate Decision: Commonwealth v. Rogers, 1992. Affirmed DNA admissibility under Frye. Rhode Island First case: In re: Case involving rape of a nursing home resident. Juvenile admitted sufficient facts to establish the charge against him; sentenced to 3 years at a juvenile facility. 1989. South Carolina First case: People v. Evans, guilty of rape/burglary, Charleston County, 1989. Appellate Decision: South Dakota First case: People v. Wimberly, guilty of rape, Meade County, 1989. Appellate Decision: State v. Wimberly. Affirmed use of evidence and statistics. Data Bank established: 1990 Tennessee First case: FBI testimony in rape case in Blountville results in admission of DNA evidence, 1989, Trial pending. Appellate Decision: People v. Harris, 1992. Affirmed admissibility and frequency estimate under both Frye and relevancy test. Data Bank established: 1991 Legislated Admissibility passed: 1991 Texas First case: People v. Trimboli, A DNA test that triple-murder defendant Ronald Trimboli had hoped would clear his name instead gave prosecutors additional evidence against him. Tests concluded that semen found on the bedspread where one of the three victims was raped matched a sample Trimboli had given for the test. Trimboli's two earlier trials for the three murders both ended in mistrials, first because of jury misconduct and later because a jury deadlocked, 6 to 6. The third trial resulted in a conviction on all three counts of murder. Tarrant County, test in 1988, convicted in 1989. Appellate Decision: Kelly v. Texas, 1992. Affirmed DNA admissibility and concluded Frye was no longer part of Texas law. Utah First case: People v. Bickmore, DNA evidence admitted, mistrial declared on other grounds, Ogden, 1989. Data Bank established: 1994 Vermont First case: United States v. Jakobetz. Admissibility hearing pending in rape case. Defense attorney has filed request that genetic evidence not be used in court. In August 1989, judge ruled that hair, blood, and saliva samples could be taken from defendant for testing. U.S. District Court, Burlington, 1989. Virgina First case: People v. Reynolds, DNA evidence admitted in murder case, Henrico County, 1988. Appellate Decision: Spencer v. Commonwealth, 1990. Affirmed use of DNA evidence. Data Bank established: 1990 Legislated Admissibility passed: 1990 Washington First case: People v. Young. DNA tests exclude Young, who had been identified by the victim as the rapist. Charges dropped, Snohomish County, 1989. Appellate Decision: State v. Cauthron, 1993. Reversed trial court's admission of DNA match without population statistics and remanded. Data Bank established: 1990 West Virginia First case: People v. Ferrell, guilty of murder, Petersburg, 1989. Data Bank established: 1993 Wisconsin First case: People v. Banks, guilty of rape, Kenosha County, 1989. Data Bank established: 1993 Legislated Admissibility passed: 1993 Wyoming First case: Appellate Decision: Springfield v. State, 1993. Affirmed use of DNA evidence and statistical calculations. Military First case: United States v. Scott. Rape case. Military judge approved request for DNA tests, but DNA in sample too degraded to perform the testing. U.S. Marine Corps, 1988. 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