In order to process evidence in a timely manner and expedite forensic casework, certain decisions must be made regarding evidence analysis which may result in some items not being subjected to testing.
Prior to the analysis of evidentiary material, an evaluation of the important elements of the case shall be obtained through communication with the submitting agency and/or prosecuting officials (e.g., submission forms, police reports, medical reports, discussions with investigators). This evaluation shall include an assessment of the evidence and its relevance. Depending on the circumstances of each case, the Scientist will determine which exhibits will be analyzed and which tests will be performed, and shall also have the option to limit screening and/or testing to probative evidence only.
For suspected controlled substance cases, a sampling plan may be used where only a specific number or weight of sufficiently similar items is analyzed. Generally, once a penalty weight threshold has been reached, the Scientist will not analyze any similar remaining evidence in that case. In general, drug paraphernalia will not be analyzed unless it is the only exhibit submitted in the case.
For cases (such as homicides) where there may be numerous stains of blood or other body fluids, testing may only be performed on a sampling of these stains – especially if it is likely that all of the stains originated from the same source.
Per Texas law, all Sexual Assault Evidence Collection Kits must be examined unless it has been determined by the submitting or prosecuting agency that no crime was committed. So for sexual assault cases, the Scientist will generally start the analysis with the Sexual Assault Evidence Collection Kit associated with the case, followed by the panties/underwear from the victim. Within the Sexual Assault Evidence Collection Kit, if semen is confirmed by the presence of spermatozoa on an item then the Scientist may choose not to confirm (by sperm search) other items in the kit. If sufficient probative evidence is found on items within the Sexual Assault Evidence Collection Kit (semen detected on swabs, etc.), then the Scientist may choose not to analyze additional evidence items from the case such as the underwear. Additional clothing or bedding will not generally be worked. Clothing or bedding will only be worked under special circumstances and usually after consultation with the submitting agency. Due to the unique nature of each case, which evidence items (besides the sexual assault kit) are analyzed will be at the discretion of the scientist. This will expedite casework and allow for only the most probative evidence (evidence that is most closely associated with the victim) to move forward to DNA analysis. If no probative evidence is found in the Sexual Assault Evidence Collection Kit and/or the victim’s underwear, the Scientist may contact the submitting agency and allow additional items of evidence to be submitted.
Whenever evidence items are not analyzed by the Scientist, the reason for this will be noted in the case record. Exceptions to this policy would be items clearly submitted for an analysis that is not performed at the Laboratory (gunshot residue, trace analysis, etc.), drug paraphernalia, and firearms accessories such as magazines, holsters, etc. Items submitted for DNA analysis that are not normally tested by this Laboratory (fingernail scrapings, buccal swabs, blood cards, etc.) are also exceptions under this policy and do not require an explanation when no testing is performed. The scope of testing performed by the Jefferson County Regional Crime Laboratory is listed in the Standard of Service, which submitting agencies may access by clicking on the “Customer Information” tab.
Due to the fact that the Scientist makes analytical decisions based on their knowledge of the important elements of each case, citing the Policy for Expediting Casework in the case record will be considered an acceptable explanation as to why an item is not subjected to analysis.