Jan 17 2022
Kentucky State Police Rapid DNA Program: Analyzing Sexual Assault Kits Utilizing the ANDE 6C Instrument
Today’s blog is written by guest blogger, Regina Wells, DNA Database Supervisor, Kentucky State Police Central Forensic Laboratory. Reposted from The ISHI Report with permission.
Over the past decade a spotlight has been placed on the tens of thousands of sexual assault kits that have remained untested in evidence rooms across the country. The Kentucky State Police Laboratory identified 4800 untested sexual assault kits through an audit of law enforcement agencies in the Commonwealth. This discovery prompted the Kentucky General Assembly to pass Senate Bill 63, the SAFE Act, in the spring of 2016. This sweeping legislation addressed everything from victim’s rights to officer training to evidence preservation. One of the key points of the legislation placed timeframes on hospitals, law enforcement, and the Kentucky State Police laboratory concerning the handling of sexual assault kits. Requirements for the laboratory meant by July of 2020 the average turnaround time for sexual assault kit results would need to be 60 days. With this requirement in mind in December of 2018, the KSP laboratory launched a pilot project in conjunction with the ANDE company to evaluate sexual assault kit evidence using the ANDE 6C Rapid DNA instrument.
The ANDE 6C Rapid DNA system can analyze an evidence sample in under two hours however sexual assault kits are challenging due to mixtures of the victim and suspect’s DNA. A pre-treatment step was developed by ANDE to separate the suspect DNA in sperm cells from the victim’s DNA providing clean suspect profiles which can be searched against a database. The purpose of this study was to determine if this procedure could produce a searchable suspect profile using actual evidence samples collected during a forensic sexual assault exam. Suspect profiles obtained would then be searched against a copy of the state database to determine if a hit could be obtained between the evidence profile and an offender. This would provide an officer with an investigative lead in the early stages of the investigation rather than months after the assault.
One hundred Rapid DNA sexual assault kits were provided to sexual assault nurse examiners in three jurisdictions in Kentucky for collection during a forensic sexual assault exam. Two additional swabs for the Rapid sexual assault kit were taken along with the four swabs for the traditional sexual assault kit. The Rapid sexual assault kit came directly to the laboratory while the traditional sexual assault kit was collected by law enforcement and submitted to the laboratory following their evidence handling protocols. The Rapid sexual assault kits were analyzed as quickly as possible once received into the laboratory following the ANDE protocols. Any suspect profiles obtained from the analysis were searched against a copy of the state database, exported from CODIS, and housed in the FAIRS software. Hits obtained during this process were confirmed and reported to law enforcement as an investigative lead. The traditional sexual assault kits were fast-tracked through serology screening and DNA testing and comparisons made between the traditional DNA analysis and the results from the ANDE 6C system.
The pilot project generated fourteen searchable profiles, which at first glance appeared low. However, after serological analysis of the traditional kits, only 32 of the kits contained semen on the corresponding evidence swabs. Rapid DNA analysis produced profiles in 44% of the semen positive kits versus 59% with traditional analysis. Comparison to traditional analysis found that the ability to perform mixture interpretation and increased instrument sensitivity were the primary differences when profiles were obtained in traditional analysis only. Five database hits were obtained from the database searches including two hits identifying unknown suspects and directly leading to at least one arrest. Based on these results the laboratory concluded the ANDE 6C system can produce clean suspect profiles following the pre-treatment step when enough suspect DNA is present. This would allow the laboratory to quickly report an investigative lead to officers while the case is still on-going.
Final implementation of this program was challenging due to the lack of guidance in the FBI Quality Assurance Standards. Current rapid DNA standards are applicable to reference standards only and not crime scene samples. The laboratory’s approach was to design our methods as though it would be any other DNA process that would be subject to the standards. Validation, evidence handling, reagent quality control, and proficiency testing are all modeled after our current DNA procedures. Technicians were trained to perform the pre-processing step and operate the instruments. Modified Rapid DNA analysis was validated with a trained DNA analyst reviewing all profiles and issuing reports.
During the pilot project every kit was tested immediately, no serological analysis was completed to determine if semen was present in the kit. To increase efficiency the laboratory needed a method to identify the kits that would be the most likely to provide a profile. The laboratory had been evaluating the use of Y-screen in the months prior to the project for introduction into the casework workflow. However, the concern in sensitivity had deterred the laboratory from implementing it. Knowing that there needed to be a significant amount of male DNA present to obtain a profile using the ANDE 6C, Y-screen was explored as an option. The data from the validation allowed us to determine a threshold for male DNA that needed to be present to potentially produce a searchable profile using rapid DNA analysis. Any sexual assault kit containing 5ng or more of male DNA is routed to the Rapid DNA section for analysis.
A crucial tool for a rapid DNA program to be successful is the creation of a database to search unknown profiles against to identify suspects. ANDE provides software known as FAIRS to decrypt their data but is also capable of storing and searching DNA profiles. The laboratory designates the database maintained in the FAIRS software as the Rapid SDIS. This nomenclature is used on reports along with a statement that no profiles were entered into CODIS. This is an effort to differentiate the two processes and ensure there is no confusion about where the rapid DNA profiles are being stored. CODIS is still an important tool in the laboratory to identify suspects so any kits that do not produce a hit will have traditional analysis performed for CODIS entry. This will also be the procedure for those cases entering the court system as rapid DNA analysis has not been introduced into Kentucky courts.
Kentucky’s Rapid DNA program came online July 15th. Only 22 rapid sexual assaults kits have been submitted thus far to the laboratory. 23% of the kits that have been Y-screened have qualified for rapid DNA analysis. Currently the laboratory receives approximately 950 sexual assault kits in a year. If this number holds true, the rapid DNA program could potentially process over 200 of those sexual assault kits. The average turnaround time from time the kit arrives at the laboratory until the report is complete is currently seven days. While the sexual assault kit program was the primary focus for implementing rapid DNA the laboratory validated its use for other casework samples. Blood and saliva evidence as well as human remains testing are all currently being analyzed on the ANDE 6C as part of the Kentucky State Police’s rapid program.
As with any new technology in forensic science there are challenges in designing and implementing a program such as this. There were no other laboratories to share protocols and procedures with or provide answers when questions arose. With no clear-cut guidance in standards and accreditation documents our laboratory as well as our auditors have had to find a way to apply current standards to this program. As the technology advances and more laboratories implement their own programs these impediments should resolve over time. With only months of casework under our belt, the Kentucky State Police Laboratory has already processed and reported results in timeframes that were previously outside of our reach demonstrating the work is worth the reward.
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