Evidentiary discrepancies in sexual assault casework within the US

Abstract

In recent years, a significant number of investigations have discovered up to 200 000 unsubmitted sexual assault kits (SAKs) in the US. While the public outcry was largely directed towards DNA analysis, the SAKs also contained biological specimens specifically designated for toxicological analysis. Due to the sensitivity of analytes in potential drug facilitated sexual assaults, the preservation and maintenance of the specimens is crucial in providing accurate toxicological measurements. The investigations into the unsubmitted SAKs have identified subjective law enforcement officer (LEO) rationale for the unsubmitted kits, however the impact on toxicological specimens has not been examined. This brief review of policies and guidelines with respect to forensic specimens has identified potential sources of evidentiary degradation, despite the use of chemical preservatives. With respect to temperature-controlled environments, the variation in SAK submission policies established throughout the US are potentially detrimental to the preservation of toxicological evidence. Degradation as a result of time-delayed collection and poorly maintained storage temperatures plays a crucial role for/in the interpretation of qualitative and quantitative toxicological results. This review finds these delays can be addressed through modernisation of facilities; electronic tracking of unsubmitted SAKs; mandated transfer of biological evidence within 72 h; and documentation of temperature within the chain of custody or other records. Without identifying the range of temperatures in which the evidence was exposed, forensic toxicologists may unintentionally provide erroneous interpretations of toxicological analyses -potentially casting doubt on the survivor's recall of events and negatively impacting future sexual assault investigations. KEY POINTS• Temperature-controlled conditions for biological evidence of sexual assault cases may be inadequate in the US. • Biological specimens collected in drug-facilitated sexual assault (DFSA) casework must be immediately preserved in optimal temperature-controlled temperatures. • If biological specimens are not stored at optimal temperatures, forensic toxicologists are likely to interpret values that do not reflect the specimen at time of collection. • It would benefit DFSA investigations and toxicological interpretations if temperature-related information was included with the chain of custody or other included documentation.

The viability assured by the chain of custody

“…Effectively, it was mentioned that the results may also be affected in the analyses level, either by the temperature that they are exposed to but also by a late analysis. It was also observed that there is a higher percentage of positive cases when the harvest occurs within 24 hours [4]. Conclusions: The chain of custody procedures can be adapted to the circumstances, but its universal that the fail of a procedure is a source of error.…”

“…All this makes the invalidity of the results possible, but may also lead to false conclusions and interpretations. [1,4] Keywords: chain of custody; evidence collection; forensic sciences.…”

Interpol review of forensic management, 2019–2022

“…Whether due to a police officer's reluctance to submit these kits for testing, or the backlogs experienced in many laboratories due to resource constraints, the result for many victims is “justice denied” [ 82 , 132 ]. With the recent #MeToo movement and negative media attention on untested SAKs stored in many jurisdictions as long as decades [ 148 ], and worse SAKs destroyed or degraded either intentionally [ 149 ] or unintentionally [ 150 ], the public's demands to do something has grown [ 85 ].…”