CODIS – a System of Pointers
Fighting Crime Using the US Database of DNA Profiles
The Combined DNA Index System, CODIS, combines computer and DNA technologies into an effective tool for fighting violent crime and finding missing persons.
CODIS (Combined DNA Index System), an electronic database of DNA profiles, is similar to the AFIS (Automated Fingerprint Identification System) database. Just as fingerprints found at a crime scene can be run through AFIS in search of a suspect or a link to a crime scene, DNA profiles from a crime scene can be entered into CODIS.
History of CODIS - Combined DNA Index System
In late 1990, the FBI Laboratory began a pilot project with six state and local crime laboratories to develop software to support each lab's DNA testing and allow sharing of DNA profiles with other crime laboratories.
The DNA Identification Act of 1994 formally authorized the FBI to operate CODIS and set national standards for forensic DNA testing as an effective method of fighting crime.
What is CODIS?
CODIS is a computer software program that operates local, State, and national databases of DNA profiles from convicted offenders, unsolved crime scene evidence, and missing persons. Every State in the USA has a statutory provision for the establishment of a DNA database that allows for the collection of DNA profiles from offenders convicted of particular crimes.
The CODIS databse is a system of pointers; the database only contains information necessary for making matches.
A record in the CODIS database, known as a CODIS profile, consists of a specimen identifier, an identifier for the laboratory responsible for the profile, and the results of the DNA analysis (known as the DNA profile). Other than the DNA profile, CODIS does not contain any personal identity information. CODIS does not store criminal history information, case-related information, social security numbers or dates-of-birth.
CODIS - Investigative Leads in Crime Scene Evidence
CODIS uses two main indexes to generate investigative leads in crimes where biological evidence is recovered from a crime scene.
* Convicted Offender Index. The Convicted Offender Index contains DNA profiles of individuals convicted of crimes ranging from certain misdemeanors to sexual assault and murder.
* Forensic Index. The Forensic Index contains DNA profiles obtained from crime scene evidence like as semen, saliva, or blood.
Other CODIS Indexes - Arrestee, Missing Persons
CODIS also has several other indexes, including: an Arrestee Index, a Missing or Unidentified Persons Index, and a Missing Persons Reference Index.
CODIS is very successful in:
- linking serial cases
- missing persons’ cases
- matching crime scene evidence to known convicted offenders
Matches Between Profiles in Indexes
A match made between profiles in the forensic index can link crime scenes to each other, possibly identifying serial offenders.
Matches made between the Forensic and Convicted Offender Indexes can provide investigators with the identity of a suspect. In a crime scene investigation, when an “offender hit” is obtained, the information is used as probable cause to obtain a new DNA sample from that suspect so that the match can be confirmed by the crime laboratory before an arrest is made.
The CODIS System has Three Tiers
The system has three tiers (or levels): local, state, and national. The National DNA Index System, or NDIS, is operated by the FBI. NDIS provides a mechanism for forensic crime laboratories located throughout the United States to share and exchange DNA profiles.
According to the FBI, as of October 2007 the profile composition of the National DNA Index System (NDIS) is as follows:
- Total number of profiles: 5,265,258
- Total Forensic profiles: 194,785
- Total Convicted Offender profiles: 5,070,473
DNA Database Privacy Concerns
Currently all fifty states in the USA have mandatory DNA collection from sex offenders and nearly 40 states from all convicted felons. Other states collect DNA samples from juveniles and all suspects arrested. The American Civil Liberties Union (ACLU) is concerned with the increased use of collecting DNA from arrested suspects rather than only DNA testing for convicted felons. Along with the ACLU, other civil libertarians also oppose the use of a DNA database for privacy concerns.
Sources:
President’s DNA Initiative – Advancing Justice Through DNA Technology
