View source for Combined DNA Index System

{{Short description|United States national DNA database}}
{{good article}}
[[File:CODIS logo.png|thumb|CODIS logo]]
{{Forensic science|expanded=all}}
{{Use mdy dates|date=September 2011}}
The '''Combined DNA Index System''' ('''CODIS''') is the [[United States]] [[national DNA database]] created and maintained by the [[Federal Bureau of Investigation]]. CODIS consists of three levels of information; Local DNA Index Systems (LDIS) where DNA profiles originate, State DNA Index Systems (SDIS) which allows for laboratories within states to share information, and the National DNA Index System (NDIS) which allows states to compare DNA information with one another.

The CODIS software contains multiple different databases depending on the type of information being searched against. Examples of these databases include, missing persons, convicted offenders, and forensic samples collected from crime scenes. Each state, and the federal system, has different laws for collection, upload, and analysis of information contained within their database. However, for privacy reasons, the CODIS database does not contain any personal identifying information, such as the name associated with the DNA profile. The uploading agency is notified of any hits to their samples and are tasked with the dissemination of personal information pursuant to their laws.

== Establishment ==
The creation of a national DNA database within the U.S. was first mentioned by the Technical Working Group on DNA Analysis Methods (TWGDAM) in 1989.<ref name="Origin" /> The FBI's strategic goal was to maximize the voluntary participation of states and avoid what happened several years early, when eight western states frustrated with the progress creating a national [[Integrated Automated Fingerprint Identification System|Automated Fingerprint Identification System]] (AFIS) network formed the Western Identification Network (WIN).<ref>{{Cite web |title=What WIN Is |url=https://www.winid.org/public/what-win-is/ |access-date=2023-09-27 |website=Western Identification Network |language=en-US}}</ref> The FBI's strategy to discourage states from creating systems that competed with CODIS was to develop DNA databasing software and provide it free of charge to state and local crime laboratories.This strategic decision--to provide software free of charge for the purpose of gaining market share--was innovative at that time and predated the [[browser wars]]. In 1990, the FBI began a pilot DNA databasing program with 14 state and local laboratories.<ref name="Pilot" /> 

In 1994, Congress passed the [[DNA Identification Act (1994)|DNA Identification Act]] which authorized the FBI to create a national DNA database of convicted offenders as well as separate databases for missing persons and forensic samples collected from crime scenes. (Some in the Bureau believed the Act was not required to establish a national DNA database because the FBI's [[FBI Criminal Justice Information Services Division|Criminal Justice Information Services Division]] was already using similar authorities to provide data-sharing solutions to federal, state, local, and tribal law enforcement agencies.) The DNA Identification Act also required that laboratories participating in the CODIS program maintain [[accreditation]] from an independent nonprofit organization that is actively involved in the forensic fields and that scientists processing DNA samples for submission into CODIS maintain proficiency and are routinely tested to ensure the quality of the profiles being uploaded into the database.<ref name="DNA1994" /> The national level of CODIS (NDIS) was implemented in October 1998. Today, all 50 states, the [[Washington D.C.|District of Columbia]], federal law enforcement, the [[Army CID|Army Laboratory]], and Puerto Rico participate in the national sharing of DNA profiles.<ref name="NDISfacts" />

== Database structure ==

The CODIS database contains several different indexes for the storage of DNA profile information. For assistance in criminal investigations three indexes exist: the offender index, which contains DNA profiles of those convicted of crimes; the arrestee index, which contains profiles of those arrested of crimes pursuant to the laws of the particular state; and the forensic index, which contains profiles collected from a crime scene.<ref name="Indexes" /> Additional indexes, such as the unidentified human remain index, the missing persons index, and the biological relatives of missing persons index, are used to assist in identifying missing persons.<ref name="Indexes" /> Specialty indexes also exist for other specimens that do not fall into the other categories. These indexes include the staff index, for profiles of employees who work with the samples, and the multi-allelic offender index, for single-source samples that have three or more [[allele]]s at two or more [[Locus (genetics)|loci]].<ref name="Other Indexes" />

=== Non-criminal indexes ===

While CODIS is generally used for linking crimes to other crimes and potentially to suspects there are non-criminal portions of the database such as the missing person indexes. The [[National Missing Person DNA Database]], also known as CODIS(mp), is maintained by the FBI at the NDIS level of CODIS allowing all states to share information with one another. Created in 2000 using the existing CODIS infrastructure, this section of the database is designed to help identify human remains by collecting and storing DNA information on the missing or the relatives of missing individuals.<ref name="NMPDD" /><ref name="Missing" /> Unidentified remains are processed for DNA by the [[University of North Texas Center for Human Identification]] which is funded by the [[National Institute of Justice]].<ref name="UNT" /> Nuclear, [[Y-STR]] (for males only), and mitochondrial analysis can be performed on both unknown remains and on known relatives in order to maximize the chance of identifying remains.<ref name="NMPDD" />

=== Statistics ===

{{As of|2020|09}}, NDIS contained more than 14 million offender profiles, more than four million arrestee profiles and more than one million forensic profiles.<ref name=":0">{{Cite web|date=September 2020|title=CODIS – NDIS Statistics as of September 2020|url=https://www.fbi.gov/services/laboratory/biometric-analysis/codis/ndis-statistics|access-date=2020-11-06|website=Federal Bureau of Investigation|language=en-us}}</ref><ref name="Statistics" /> The effectiveness of CODIS is measured by the number of investigations aided through database hits. {{As of|2020|09}}, CODIS had aided in over 520 thousand investigations and produced more than 530 thousand hits.<ref name=":0" /><ref name="Statistics" /> Each state has their own SDIS database and each state can set their own inclusionary standards that can be less strict than the national level. For this reason, a number of profiles that are present in state level databases are not in the national database and are not routinely searched across state lines.<ref name="SDIS diff" />

== Scientific basis ==

The bulk of identifications using CODIS rely on short tandem repeats ([[Microsatellite|STRs]]) that are scattered throughout the human genome and on statistics that are used to calculate the rarity of that specific profile in the population.<ref name="STRstats" /> STRs are a type of [[copy-number variation]] and comprise a sequence of [[nucleotide]] [[base pair]]s that is repeated over and over again. At each location tested during DNA analysis, also known as a locus (plural loci), a person has two sets of repeats, one from the father and one from the mother.  Each set is measured and the number of repeat copies is recorded.<ref name="STRs" /> If both strands, inherited from the parents, contain the same number of repeats at that locus the person is said to be [[homozygous]] at that locus. If the repeat numbers differ they are said to be [[heterozygous]]. Every possible difference at a locus is an allele.<ref name="Zygosity" /> This repeat determination is performed across a number of loci and the repeat values is the DNA profile that is uploaded to CODIS. As of January&nbsp;1, 2017, requirements for upload to national level for known offender profiles is 20 loci.<ref name="NDISfacts" />

Alternatively, CODIS allows for the upload of [[mtDNA|mitochondrial DNA]] (mtDNA) information into the missing persons indexes. Since mtDNA is passed down from mother to offspring it can be used to link remains to still living relatives who have the same mtDNA.<ref name="NDISfacts" />

=== Loci ===
[[File:Codis profile.jpg|thumb|right|The original 13 core loci and their locations on the genome plus the sex determining locus [[amelogenin]] (AMEL)]]

Prior to January 1, 2017, the national level of CODIS required that known offender profiles have a set of 13 loci called the "CODIS core". Since then, the requirement has expanded to include seven additional loci. Partial profiles are also allowed in CODIS in separate indexes and are common in crime scene samples that are degraded or are mixtures of multiple individuals. Upload of these profiles to the national level of CODIS requires at least eight of the core loci to be present as well as a profile rarity of 1 in 10 million (calculated using population statistics).<ref name="NDISfacts" />

Loci that fall within a [[gene]] are named after the gene. For example, TPOX, is named after the [[Thyroid peroxidase|human '''t'''hyroid '''p'''er'''ox'''idase]] gene.<ref name="TPOXname" /> Loci that do not fall within genes are given a standard naming scheme for uniformity. These loci are named D + the [[chromosome]] the locus is on + S + the order in which the location on that chromosome was described. For example, D3S1358 is on the third chromosome and is the 1358th location described.<ref name="Nomenclature" /> The CODIS core are listed below; loci with asterisks are the new core and were added to the list in January 2017.<ref name="CORENIST" />

{{columns-list|colwidth=22em|
* CSF1PO
* D3S1358
* D5S818
* D7S820
* D8S1179
* D13S317
* D16S539
* D18S51
* D21S11
* FGA
* TH01
* TPOX
* vWA
* D1S1656*
* D2S441*
* D2S1338*
* D10S1248*
* D12S391*
* D19S433*
* D22S1045*
}}

The loci used in CODIS were chosen because they are in regions of [[noncoding DNA]], sections that do not code for proteins. These sections should not be able to tell investigators any additional information about the person such as their hair or eye color, or their race.<ref name="noncoding" /> However, new advancements in the understanding of genetic markers and ancestry have indicated that the CODIS loci may contain [[Phenotype|phenotypic]] information.<ref name="Phenotypic" /><ref name="Phenotype2" />

== International use ==

While the U.S. database is not directly connected to any other country, the underlying CODIS software is used by other agencies around the world. {{As of|2016|04}}, the CODIS software is used by 90 international laboratories in 50 countries.<ref name="Pilot" /><ref name="Phenotypic" /> International police agencies that want to search the U.S. database can submit a request to the FBI for review. If the request is reasonable and the profile being searched would meet inclusionary standards for a U.S. profile, such as number of loci, the request can be searched at the national level or forwarded to any states where reasonable suspicion exists that they may be present in that level of the database.<ref name="NDISfacts" />

== Controversies ==

=== Arrestee collection ===
[[File:CODIS arrestee collections.svg|right|thumb|Current laws governing DNA collection as of 2023.<p>{{Legend0|#0055d4|Collection upon conviction only}}<br>{{Legend0|#FFDB58|Collection from some felony arrests}}<br>{{Legend0|#00A86B|Collection from all felony arrests}}</p>]]
The original purpose of the CODIS database was to build upon the [[Sex offender registries in the United States|sex offender registry]] through the DNA collection of convicted sex offenders.<ref name="Offender" /> Over time, that has expanded. Currently, all 50 states collect DNA from those convicted of [[felony|felonies]]. A number of states also collect samples from juveniles as well as those who are arrested, but not yet convicted, of a crime.<ref name="Statistics" /><ref name="Juvenile" /> Note that even in states which limit collection of DNA retained in the state database only to those convicted of a crime, local databases, such as the forensic laboratory operated by New York City's Office of Chief Medical Examiner, may collect DNA samples of arrestees who have not been convicted. The collection of arrestee samples raised constitutional issues, specifically the [[Fourth Amendment to the United States Constitution|Fourth Amendment]] prohibiting unreasonable [[search and seizure]]. It was argued that the collection of DNA from those that were not convicted of a crime, without an explicit order to collect, was considered a warrantless search and therefore unlawful.<ref name="Arrestee4th" /> In 2013, the United States Supreme Court ruled in ''[[Maryland v. King]]'' that the collection of DNA from those arrested for a crime, but not yet convicted, is part of the police booking procedure and is reasonable when that collection is used for identification purposes.<ref name="ArresteeOK" />

=== Familial searching ===

{{further information|Familial searching}}

The inheritance pattern of some DNA means that close relatives share a higher percentage of alleles between each other than with other, random, members of society.<ref name="Familial" /> This allows for the searching of close matches within CODIS when an exact match is not found. By focusing on close matches, investigators can potentially find a close relative whose profile is in CODIS narrowing their search to one specific family. Familial searching has led to several convictions after the exhaustion of all other leads including the [[Grim Sleeper]] serial killer.<ref name="Grim Sleeper" /> This practice also raised Fourth Amendment challenges as the individual who ends up being charged with a crime was only implicated because someone else's DNA was in the CODIS database.<ref name="Familial4th" /> {{As of|2018|04}}, twelve states have approved the use of familial searching in CODIS.<ref name="AZFamilial" />

==See also==
* [[Debbie Smith Act]]
* [[GEDmatch]]
* [[Integrated Automated Fingerprint Identification System]] (IAFIS)

== References ==
{{Reflist|30em|refs=

<ref name="Origin">{{cite web | title=CODIS and PCR-Based Short Tandem Repeat Loci: Law Enforcement Tools | last1=Budowle | first1=Bruce | last2=Moretti | first2=Tamyra R. | last3=Niezgoda | first3=Stephen J. | last4=Brown | first4=Barry L. | url=https://www.promega.com/~/media/files/resources/conference%20proceedings/ishi%2002/oral%20presentations/17.pdf | access-date=October 8, 2016 | publisher=Promega}}</ref>

<ref name="Pilot">{{cite web | title=Combined DNA Index System (CODIS) | url=https://www.fbi.gov/services/laboratory/biometric-analysis/codis#CODIS-Overview | publisher=Federal Bureau of Investigation | access-date=May 8, 2018}}</ref>

<ref name="DNA1994">{{USC2|42|14132|Index to facilitate law enforcement exchange of DNA identification information}}</ref>

<ref name="NDISfacts">{{cite web | title=Frequently Asked Questions on CODIS and NDIS | url=https://www.fbi.gov/services/laboratory/biometric-analysis/codis/codis-and-ndis-fact-sheet | access-date=March 6, 2017 | publisher=Federal Bureau of Investigation}}</ref>

<ref name="STRstats">{{cite web | title=What are the 13 core CODIS loci? | url=http://www.biology.arizona.edu/human_bio/activities/blackett2/str_codis.html | date=October 27, 2000 | access-date=March 6, 2017 | via=The University of Arizona | publisher=The Biology Project}}</ref>

<ref name="STRs">{{cite web | title=Forensics: Fingering Criminals Using DNA | url=http://www.dummies.com/education/science/forensics-fingering-criminals-using-dna/ | access-date=March 6, 2017 | website=For Dummies}}</ref>

<ref name="Zygosity">{{cite web | title=Genetics of STR Inheritance | url=http://www.biology.arizona.edu/human_bio/activities/blackett2/str_inheritance.html | date=October 27, 2000 | access-date=March 7, 2017 | via=The University of Arizona | publisher=The Biology Project}}</ref>

<ref name="noncoding">{{cite web | title=Germany Mulls DNA Database Identifiers of Hair, Eye Color, Ethnicity | date=March 27, 2017 | access-date=April 1, 2017 | url=http://www.forensicmag.com/news/2017/03/germany-mulls-dna-database-identifiers-hair-eye-color-ethnicity | last=Augenstein | first=Seth | publisher=Forensic Magazine}}</ref>

<ref name="Phenotypic">{{cite magazine | title=Does CODIS Contain Untapped Ancestry Information? | date=April 13, 2016 | access-date=April 1, 2017 | url=https://www.forensicmag.com/article/2016/04/does-codis-contain-untapped-ancestry-information | last=Augenstein | first=Seth | magazine=Forensic Magazine}}</ref>

<ref name="Phenotype2">{{cite magazine | title=CODIS Has More ID Information Than Believed, Scientists Find | last=Augenstein | first=Seth | date=May 15, 2017 | access-date=May 16, 2017 | url=http://www.forensicmag.com/news/2017/05/codis-has-more-id-information-believed-scientists-find | magazine=Forensic Magazine}}</ref>

<ref name="Nomenclature">{{cite book | title=Forensic DNA Typing: Biology, Technology, and Genetics of STR Markers | last=Butler | first=John M. | publisher=Elsevier Academic Press | edition=2nd | via=Google Books | date=2005 | access-date=April 2, 2017 | pages=23–24 | url=https://books.google.com/books?id=gwDyBq2xLjIC&pg=PA23| isbn=9780080470610 }}</ref>

<ref name="TPOXname">{{cite web | title=TPOX | url=http://www.cstl.nist.gov/strbase/str_TPOX.htm | publisher=National Institute of Standards and Technology | access-date=April 2, 2017}}</ref>

<ref name="Indexes">{{cite web | title=Data and Communication Flow in CODIS | url=https://sakitta.org/resources/docs/Data-and-Communication-Flow-in-CODIS.pdf | access-date=April 9, 2017 | publisher=Sexual Assault Kit Initiative}}</ref>

<ref name="Other Indexes">{{cite web | title=Procedure for CODIS | url=http://www.ncdoj.gov/getdoc/183aa47b-4b50-4af9-8c56-e3fb7e4b131d/CODIS-04-18-2014.aspx | version=10 | date=December 28, 2015 | access-date=May 13, 2017 | publisher=North Carolina Department of Justice}}</ref>

<ref name="Statistics">{{cite web | title=CODIS – NDIS Statistics | url=https://www.fbi.gov/services/laboratory/biometric-analysis/codis/ndis-statistics | access-date=May 13, 2017 | publisher=Federal Bureau of Investigation}}</ref>

<ref name="SDIS diff">{{cite report | title=Toward a Comparison of DNA Profiling and Databases in the United States and England | last1=Goulka | first1=Jeremiah | last2=Matthies | first2=Carl | last3=Disley | first3=Emma | last4=Steinberg | first4=Paul | date=2010 | access-date=May 14, 2017 | url=http://www.rand.org/content/dam/rand/pubs/technical_reports/2010/RAND_TR918.pdf | publisher=[[RAND Corporation]] | page=6}}</ref>

<ref name="AZFamilial">{{cite magazine | title=Arizona Nabs Murder Suspect With Familial DNA Searching on First Try | last=Augenstein | first=Seth | date=April 11, 2018 | access-date=April 11, 2018 | url=https://www.forensicmag.com/news/2018/04/arizona-nabs-murder-suspect-familial-dna-searching-first-try | magazine=Forensic Magazine}}</ref>

<ref name="Offender">{{cite journal | journal=Federal Register | volume=63 | issue=118 | date=June 19, 1998 | access-date=May 21, 2017 | url=https://www.gpo.gov/fdsys/pkg/FR-1998-06-19/html/98-16391.htm | publisher=Federal Register Online | via=Government Publishing Office | pages=33696–33708 | title=Proposed Guidelines for the Jacob Wetterling Crimes Against Children and Sexually Violent Offender Registration Act, as Amended}}</ref>

<ref name="Juvenile">{{cite report | title=Collecting DNA from Juveniles | last1=Samuels | first1=Julie E. | last2=Dwyer | first2=Allison M. | last3=Halberstadt | first3=Robin | last4=Lachman | first4=Pamela | publisher=Urban Institute Justice Policy Center | url=http://www.urban.org/sites/default/files/publication/25021/412487-Collecting-DNA-from-Juveniles.PDF | access-date=May 21, 2017 | date=2011}}</ref>

<ref name="Arrestee4th">{{cite journal | title=Using the DNA Testing of Arrestees to Reevaluate Fourth Amendment Doctrine | date=2015 | last=Grossman | first=Steven P. | url=http://scholarworks.law.ubalt.edu/cgi/viewcontent.cgi?article=1295&context=all_fac | access-date=May 21, 2017 | journal=Valparaiso University Law Review | volume=49 | pages=659–721 | via=University of Baltimore Law}}</ref>

<ref name="ArresteeOK">{{cite web | url=https://www.nytimes.com/2013/06/04/us/supreme-court-says-police-can-take-dna-samples.html | title=Justices Allow DNA Collection After an Arrest | last=Liptak | first=Adam | date=June 3, 2013 | access-date=May 21, 2017 | website=The New York Times}}</ref>

<ref name="Familial">{{cite journal | title=Finding Criminals Through the DNA of Their Relatives – Familial Searching of the California Offender DNA Database | last1=Steinberger | first1=Eva | last2=Sims | first2=Gary | journal=Prosecutor's Brief | volume=XXXI | issue=1–2 | url=http://www.denverda.org/DNA_Documents/Familial_DNA/CDAA%20familial%20search%20article.pdf | access-date=May 21, 2017 | publisher=California District Attorneys Association | via=District Attorney's Office Denver | pages=28–32 | archive-url=https://web.archive.org/web/20160513135322/http://www.denverda.org/DNA_Documents/Familial_DNA/CDAA%20familial%20search%20article.pdf | archive-date=May 13, 2016 | url-status=dead }}</ref>

<ref name="Grim Sleeper">{{cite web | title=The controversial DNA search that helped nab the 'Grim Sleeper' is winning over skeptics | work=Los Angeles Times | date=October 25, 2016 | access-date=May 21, 2017 | last=Gerber | first=Marisa | url=http://www.latimes.com/local/lanow/la-me-familial-dna-20161023-snap-story.html}}</ref>

<ref name="Familial4th">{{cite journal | title=Policy implications for familial searching | last1=Kim | first1=Joyce | last2=Mammo | first2=Danny | last3=Siegel | first3=Mami B | last4=Katsanis | first4=Sara H | doi=10.1186/2041-2223-2-22 | journal=Investigative Genetics | date=November 1, 2011 | volume=2 | issue=22 | pages=22 | pmc=3253037 | pmid=22040348 | doi-access=free }}</ref>

<ref name="CORENIST">{{cite web | title=FBI CODIS Core STR Loci | website=National Institute of Standards and Technology | access-date=December 29, 2017 | url=http://strbase.nist.gov/fbicore.htm | date=August 26, 2015}}</ref>

<ref name="NMPDD">{{cite web | title=Missing Person Comparison Request | url=https://www.fbi.gov/services/laboratory/biometric-analysis/codis#CODIS-Overview | access-date=May 8, 2018 | publisher=Federal Bureau of Investigation}}</ref>

<ref name="UNT">{{cite web | title=Family DNA Collection Protocol | publisher=National Missing and Unidentified Persons System | url=https://identifyus.org/help/NamUs-DNA_Protocol_for_Collection.pdf | access-date=May 8, 2018 | archive-date=December 16, 2010 | archive-url=https://web.archive.org/web/20101216211631/https://identifyus.org/help/NamUs-DNA_Protocol_for_Collection.pdf | url-status=dead }}</ref>

<ref name="Missing">{{cite journal | title=Missing Person and Unidentified Remains: The Nation's Silent Mass Disaster | last=Ritter | first=Nancy | url=https://www.findthemissing.org/documents/Missing_Persons_and_Unidentified_Remains_Nations_Silent_Mass_Disaster.pdf | issue=256 | journal=NIJ Journal | publisher=National Institute of Justice | access-date=May 8, 2018}}</ref>

}}

==External links==
* [https://www.fbi.gov/how-we-can-help-you/dna-fingerprint-act-of-2005-expungement-policy CODIS page on FBI.gov]
* "[https://www.aclu.org/press-releases/aclu-warns-privacy-abuses-government-plan-expand-dna-databases ACLU Warns of Privacy Abuses in Government Plan to Expand DNA Databases]". ACLU. March 1, 1999.
* [https://www.cbsnews.com/news/a-not-so-perfect-match/ A Not So Perfect Match], [[CBS]], 2007
* "[https://web.archive.org/web/20090406135256/http://www.wsmv.com/news/17973779/detail.html DNA didn't prove anything, as it only had five points out of 13]. Juror Explains Verdict In Double Murder". November 13, 2008.

{{FBI}}

{{DEFAULTSORT:Combined Dna Index System}}
[[Category:Biometrics]]
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