All eligible DNA profiles are entered into the Combined DNA Index System (CODIS). Nationally, the CODIS DNA database contains millions of DNA profiles from convicted offenders, arrestees, crime scene samples, samples from families of missing persons and unidentified human remains. The St. Louis County Police Crime Laboratory is one of 8 CODIS laboratories in Missouri. The CODIS DNA database is administered by the FBI and only accredited crime laboratories meeting QAS requirements are allowed access. Personal information related to convicted offenders and crime scene evidence is not allowed in the CODIS database. Data is entered using case numbers and item numbers rather than names or other personal identifiers. The CODIS database enables state and local crime laboratories to compare DNA profiles electronically. CODIS is a very useful tool in solving cases that do not contain suspects and in connecting multiple crimes to a single individual. CODIS has also been instrumental in exonerations of wrongfully convicted individuals.
How are samples searched in CODIS?
Samples may be searched in CODIS at the local, state, or national level dependent upon the “Specimen Category” assigned to the DNA profile:
· Single source “Forensic Unknown” specimens are searched at the local, state, and national levels of the CODIS DNA database.
· “Forensic Mixture” and “Forensic Partial” specimens are searched at the local, state, or national levels of the CODIS DNA database dependent upon a moderate match estimation (MME) calculation. A MME statistical calculation of at least 1.00E+05 (1 in 100,000) is required for searching at the state level and 1.00E+07 (1 in 10,000,000) for the national level. Any samples not meeting the statistical threshold of 1.00E+05 (1 in 100,000) are searched at the local level only.
· “Suspect Known” specimens are entered and searched only at the local and state level of the CODIS DNA database.
What is the frequency of the searches?
Searches are conducted each business day (Monday – Friday) at all three levels (local, state, national) of the CODIS DNA database. Specimens that do not meet the above threshold(s) for upload to the state or national level of the CODIS DNA database are potentially a candidate for a “private remote search” or “one-time search”.
How long will the sample(s) remain in the database?
Specimens are retained in the CODIS DNA database indefinitely. A forensic specimen will be deleted if additional case information or CODIS hit reveals the profile originated from a victim, intimate partner, or an innocent party not related to the crime.