title: Comparing Standard and Selective Degradation DNA Extraction Methods: Results from a Field Experiment with Sexual Assault Kits<sup/>.
abstract: A growing number of U.S. cities have large numbers of untested sexual assault kits (SAKs) in police property facilities. Testing older kits and maintaining current case work will be challenging for forensic laboratories, creating a need for more efficient testing methods.
  
  
  
  We evaluated selective degradation methods for DNA extraction using actual case work from a sample of previously unsubmitted SAKs in Detroit, Michigan. We randomly assigned 350 kits to either standard or selective degradation testing methods and then compared DNA testing rates and CODIS entry rates between the two groups.
  
  
  
  Continuation-ratio modeling showed no significant differences, indicating that the selective degradation method had no decrement in performance relative to customary methods. Follow-up equivalence tests indicated that CODIS entry rates for the two methods could differ by more than ±5%. Selective degradation methods required less personnel time for testing and scientific review than standard testing.
authors.affiliation: Department of Psychology, Michigan State University, East Lansing, MI.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Campbell
authors.affiliation: Center for Statistical Training & Consultation, Michigan State University, East Lansing, MI.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Pierce
authors.affiliation: Center for Statistical Training & Consultation, Michigan State University, East Lansing, MI.
authors.forename: Dhruv B
authors.initials: DB
authors.lastname: Sharma
authors.affiliation: Department of Social Work, Boston College, Chestnut Hill, MA.
authors.forename: Jessica
authors.initials: J
authors.lastname: Shaw
authors.affiliation: Department of Psychology, Michigan State University, East Lansing, MI.
authors.forename: Hannah
authors.initials: H
authors.lastname: Feeney
authors.affiliation: Michigan State Police, Forensic Science Division, Lansing, MI.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Nye
authors.affiliation: Michigan State Police, Forensic Science Division, Lansing, MI.
authors.forename: Kristin
authors.initials: K
authors.lastname: Schelling
authors.affiliation: Harder+Company Community Research, Los Angeles, CA.
authors.forename: Giannina
authors.initials: G
authors.lastname: Fehler-Cabral
mesh_terms: D019548:Crime Victims; D004247:DNA / Q000302:isolation & purification*; D053836:DNA Degradation, Necrotic; D016172:DNA Fingerprinting; D030561:Databases, Nucleic Acid; D005260:Female; D006801:Humans; D008297:Male; D016495:Police; D012661:Semen / Q000737:chemistry; D012742:Sex Offenses; D013048:Specimen Handling / Q000191:economics / Q000295:instrumentation / Q000379:methods*
chemical_list: D004247:DNA
keywords: CODIS; DNA; forensic science; forensic testing; rape kits; selective degradation; sexual assault kits