The improvement and enlargement of the database that inculcates DNA profiles at the local, state, national orders have largely glorified law enforcement abilities to solve many cold cases. The recidivistic nature of many crimes, such as sexual assaults and burglary, a likelihood exist that the individual that committed the crime being investigated was convicted of a similar crime and already has his or her DNA profile in a DNA database that can be searched by Combined DNA Index System (CODIS).
CODIS permits the cross-comparison of DNA profiles developed from within biological evidence at crime scenes. Even if the perpetrator is being failed to be identified through the database crimes may be linked to each other, thereby aiding an investigation, eventually comes up with the identification of the suspect.
CODIS is a software program that operates local, state, and national databases of DNA profiles from convicted offenders, unsolved crime scene evidence, and missing persons. The success of CODIS is demonstrated by the thousands of matches that have linked serial cases to each other and cases that have been solved by matching crime scene evidence to known convicted offenders. The missing person index consists of the unidentified person index and the reference index.
The unidentified person index contains DNA profiles from recovered remains, such as bone, teeth, or hair. The reference index contains DNA profiles from related individuals of missing persons so that they can be periodically compared to the unidentified person index. All samples for this index are typed using mtDNA and STR DNA analysis (if possible) to maximize the power of advancing technology.
CODIS uses 2 indexes to generate investigative leads in crime for which biological evidence is recovered from a crime scene. The convicted offender index contains DNA profiles of individuals convicted of certain crimes ranging from certain misdemeanors to sexual assault and murder. Each state has different “qualifying offenses” for which persons convicted of them must submit a biological sample for inclusion in the DNA database. The forensic index contains DNA profiles obtained from crime scene evidence, such as semen, saliva, or blood. CODIS uses computer software to automatically search across these indexes for a potential match.
A description of the 3 CODIS tiers follow:-
1. Local-Typically the Local DNA Index System(LDIS) installed at crime laboratories is operated by police departments or sheriff’s offices. DNA profiles originated at the local level can be transmitted to the state and national levels.
2. State-Each state has a designated laboratory that operates the State DNA Index System(SDIS). SDIS allows local laboratories within the state to compare DNA profiles. SDIS is also the communication path between local and national tiers. SDIS is typically operated by the agency responsible for implementing and monitoring compliance with the state’s convicted offender statute.
3. National-The National DNA Index System (NDIS) is the highest level of CODIS hierarchy and enables qualified State laboratories that are actively participating in CODIS to compare DNA profiles. NDIS is maintained by the FBI under the authority of the DNA Identification Act 1994.
Written By - Chandreyee Ray
Edited By - Kashish Chadha
Social