In January 1994, the Crime Lab began accepting cases in its statewide Deoxyribonucleic Acid DNA) testing program. The DPS labs that currently provide DNA testing include Austin, Corpus Christi, El Paso, Garland, Houston, Laredo, Lubbock, Waco, and Weslaco. The DPS statewide DNA program provides this service free of charge to those agencies not supported by city and/or county crime laboratories in Dallas, Fort Worth, San Antonio, Austin and Houston.
DNA is the building block for all life. DNA may be obtained on items submitted to the Crime Laboratory Division from crime scenes including blood stains, whole blood, seminal fluid, tissue, saliva, and roots of hair. During DNA analysis, a DNA profile is developed from crime scene samples and known reference samples. Profiles provide genetic information at up to 21 locations on the DNA chain and can also indicate if the profile originated from a male (X,Y) or female (X,X) through the use of 2 additional markers. The uniqueness of a DNA profile allows the scientist to make comparisons between DNA profiles obtained from crime scene evidence and known reference sample profiles. Under proper conditions, DNA analysis enables the lab to produce positive associations between individuals and evidence as well as eliminate individuals as having contributed DNA to the evidence. Profiles are also entered into and searched in the CODIS database.
The number of cases on which DNA analysis is employed continues to increase annually at a rapid rate.