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Combined DNA Index System (CODIS) Unit


CODIS Unit Overview

The CODIS unit is responsible for performing DNA analysis on offender samples submitted from across the state.  Additionally, the CODIS Unit maintains the Oklahoma DNA Database, and enters DNA profiles developed by FBU and SFBU into CODIS.  The CODIS Unit is also responsible for notifying law enforcement of CODIS hits.

In Oklahoma, anyone convicted of a felony or one of
18 misdemeanors is required by law to submit a DNA sample to the DNA Databank.  Additionally, anyone arrested on a federal immigration charges is also required to give a DNA sample to the database.  For more information on who is required to submit a DNA sample to the DNA Database, please see Oklahoma State Statute 74.150.27a.




History of CODIS in Oklahoma

The Oklahoma DNA Database was established on July 1, 1996, after legislation was passed allowing for collection of offender samples from those persons convicted of any of approximately 23 serious felonies.  It has been amended several times over the years to add other qualifying crimes.  In 2006, Oklahoma started requiring anyone convicted of any felony to submit to DNA testing.  In 2009, 18 misdemeanors were added to the qualifying offenses.  Today, there are over one hundred thousand offender samples in the Oklahoma DNA database.

How CODIS Works

CODIS (Combined DNA Index System) is a computer system consisting of multiple databases containing DNA profiles.  CODIS has three levels:

LDIS – Local DNA Index System – local forensic laboratory level.  The LDIS contains only profiles from the local lab.  In Oklahoma, Tulsa and Oklahoma City are LDIS labs.
SDIS – State DNA Index System – state level.  The SDIS lab contains profiles from all the labs within a state.  The OSBI maintains the SDIS database for Oklahoma.
NDIS – National DNA Index System – national level.  NDIS contains profiles from all the CODIS participating labs within the United States.

Each level can have its own requirements the DNA profile must meet to qualify for entry.  The requirements are more stringent as the profile moves up through the system.

CODIS searches DNA profiles from crime scenes (forensic samples) against known offenders (offender samples) and other crime scenes.  When two samples match, the match is verified by an analyst.  A verified match is called a “Hit”.  A hit can be between two cases (Forensic Hit) or between a case and an offender (Offender hit).  Hits are reported to law enforcement for further investigation.

CODIS can also help identify unidentified remains.  Families with missing loved ones can submit DNA samples to CODIS.  These DNA samples are searched against profiles developed from human remains that haven’t been identified through other methods.  Unidentified remains are also searched against offender samples.  Samples from relatives of missing persons are only searched against human remains and are removed if the loved one is found.


Offender DNA Analysis

Offender DNA Analysis is performed in a similar manner to the DNA analysis conducted by FBU and SFBU.  The major differences are that the CODIS Unit analyzed approximately 90 samples at a time and does not extract or quantitate the DNA.  The CODIS Unit is able to directly amplify the DNA from the offender collection card, and then analyze it on the Genetic Analyzer.  The direct amplification method allows for higher throughput with less hands-on time.