The Combined DNA Index System and its applications in criminal investigations

Combined DNA Index System (codis)

Overview of CODIS

Uses of CODIS

CODIS Applications

CODIS Limitations

Future of CODIS

COMBINED DNA INDEX SYSTEM (CODIS)

The objective of this work is to explain CODIS, which is the 'Combined DNA Index System'. This work will report on the historical information relating to CODIS and explain its use, applications, limitations, and the predicted and probable future of CODIS and will do so in a manner that the layperson enables the comprehension of the layperson related to CODIS.

CODIS is the abbreviation for the 'Combined DNA Index System'. This database was established by the Federal Bureau of Investigation for storing the profiles of individuals who are convicted offenders that are used in investigations in all U.S. states to assist in solving crimes. CODIS exists in all 50 U.S. states and profile approximately 80,302 individuals documenting biological evidence. This forensic evidence documents unknown offenders as well from evidence gathered at the scene of crimes. All of this information is stored in the CODIS database which is installed in approximately 137 laboratories in 49 states across the nation as well as in the District of Columbia. (Combined DNA Index System, nd)

Estimates from the FBI stats that 67% of rapists who were convicted have committed two or even more sexual assaults that were not detected. (Department of Justice, 2001) There are two approaches in DNA matching which are:

1) direct matching; and 2) kinship matching. (President's DNA Imitative, 2007)

Direct matching makes a comparison of two DNA profiles in order to determine whether they came from the same individual. This type of matching gives consideration to allelic dropout for nuclear DNA and heteroplasmy for mtDNA. Kinship matching, uses the DNA profile in order to make identification of biological relationships. Considered in this type of matching are allelic dropout, or the nuclear DNA of the individual and mutations, or the nuclear and mtDNA. (Ibid; paraphrased)

II. Uses of CODIS

There are several uses of DNA evidence in criminal justice. Some of those uses are the ones as follows provided with a description of each as well.

Solving Cold Cases:

Recent advances in DNA technology make it possible for law enforcement agencies to solve cases that went unsolved in years past. The President's DNA initiative points out the fact that there is evidence that the naked eyes will certainly miss but that may very well be the needed clue in solving a crime.

Post-Conviction Testing:

DNA testing is not only for the purpose of conviction but as well has been a method used for exoneration of those who have been falsely accused and are innocent. The handling of DNA, that is, the methods used for collection, preservation and testing of DNA is absolutely critical to successful use in cases whether for the purpose of conviction or exoneration of a crime.

Identification in Incidents with Mass Fatalities:

In response to the need for identification of victims following the September 11, 2001, attack of the World Trade Center (WTC) in New York "City the National Institute of Justice (NIJ) which is the agency within the U.S. Department of Justice that conducts research, development and evaluation for the Department, called together experts in order to collaborate relating to support and advice during the efforts of identifying the 2,792 victims. This was a huge undertaking in consideration of the condition of the victims and the length of time the recovery took.

Missing Persons Identification:

CODIS is used in identification of missing individuals which totaled approximately 5.000 at the time of the report of the 'President's DNA Initiative'.

Solving Crimes Relating to Property:

Property crimes are the type of crimes that tend to reoccur and often escalate in terms of violence and unfortunately often are not solved.(Langan and Levin, 1994) Estimates state that "each burglar in the top 10% of burglars commits more than 232 burglaries per year. (Chaiken and Chaiken, 1982) it has been discovered by police departments that DNA from a burglary can be analyzed and often results in the solving of other cases simultaneously. Findings state that biological evidence that is collected from the crime scene of a property crime has the potential to prevent crimes in the future. (President's DNA Initiative, 2007)

DNA and Wildlife Forensics:

Wildlife forensic applications use evidence that has been scientifically analyzed concerning legal issues relating to wild animals whether is be due the animal being a victim or the perpetrator upon a person. The National Fish and Wildlife Forensic Laboratory utilizes DNA for conservation, protection and enhancement of wildlife and plants. Trent University Wildlife Forensic DNA Laboratory utilizes DNA for different wildlife issues.

III. CODIS Applications

Only a few cells may be enough information to make the DNA information useful in a court case. The following chart labeled Figure 2 lists the evidence, the possible location of DNA on the evidence, and the source of DNA that may be a powerful tool in conviction or exoneration of a case.

DNA Evidence, Location on Evidence and DNA Source Evidence

Possible Location of DNA on the Evidence

Source of DNA baseball bat or similar weapon handle, end sweat, skin, blood, tissue hat, bandanna, or mask inside sweat, hair, dandruff eyeglasses nose or ear pieces, lens sweat, skin facial tissue, cotton swab surface area mucus, blood, sweat, semen, ear wax dirty laundry surface area blood, sweat, semen toothpick tips saliva used cigarette butt saliva stamp or envelope licked area saliva tape or ligature inside/outside surface skin, sweat bottle, can, or glass sides, mouthpiece saliva, sweat used condom inside/outside surface semen, vaginal or rectal cells blanket, pillow, sheet surface area sweat, hair, semen, urine, saliva through and through" bullet outside surface blood, tissue bite mark person's skin or clothing saliva fingernail, partial fingernail scrapings blood, sweat, tissue

Source: National Institute of Justice

IV. CODIS Limitations

Stated as a limitation of the use of CODIS is that in mass fatality incidents it is reported that each human remain is likely to match several samples. It is not to say a person would go unidentified but instead the limitation would be that individuals would be identified multiple times. Another limitation that exist with the CODIS system is that contamination or degradation of a sample may inhibit the ability to make a genetic profile. (Cheng, Garofalo, Keung, Li, Nguyen, and Wharton, 2006) Instructions provided for avoidance of contamination of degradation of samples are inclusive of the following: (1) "Wear gloves. Change them often; (2) Use disposable instruments or clean them thoroughly before and after handling each sample; (3) Avoid touching the area where you believe DNA may exist; (4) avoid talking, sneezing, and coughing over evidence; (5) Avoid touching your face, nose, and mouth when collecting and packaging evidence; (6) Air-dry evidence thoroughly before packaging; and (7) Put evidence into new paper bags or envelopes, not into plastic bags. Do not use staples." (National Institute of Justice, 2007)

V. Future of CODIS

The work entitled: "Communication, Documentation and Information Services" states that in the future CODIS will "continue to place a major emphasis on upgrading technology in all areas of its responsibility." (Vest of Research, nd) in a National Institute of Justice report entitled: "The Future of Forensic DNA Testing: Predictions of the Research and Development Working Group" published in November 2000 states that "technology projections for 2010" include transition to new technologies to supplement what is already in place.

The National Institute of Justice report predicts that by 2010 there will be miniature, portable instruments that can be used at the scene of the crime for analysis and be capable of computer linked remote analysis allowing for rapid identification of suspects and quick elimination of innocent suspects. (NIJ, 2000) Predicted as well that that the techniques used in handling DNA that is very small or that has suffered degradation will be refined. Finally, the National Institute of Justice predicts that more and more suspects will be identified through database searches in the future.