Sexual Assault Kit Backlog Study, Los Angeles, California, 1982-2010 (ICPSR 33841)

Time Period(s) View help for Time Period(s)

Date of Collection View help for Date of Collection

Data Collection Notes View help for Data Collection Notes

Study Purpose View help for Study Purpose

The study had four primary objectives: (1) To describe and evaluate the results of new scientific tests performed by various private laboratories on backlogged sexual assault kit evidence outsourced from departmental crime labs; (2) to review the sexual assault case processing literature and the role played by evidence and other factors in solving and prosecuting such cases; (3) to determine the criminal justice dispositions of a sample of backlogged and non-backlogged cases before and after kit testing; and (4) to identify principal case and evidence characteristics that could be used by forensic laboratories.

Study Design View help for Study Design

The research team principally examined information contained in the crime laboratory records of the Los Angeles Sheriff's Department (LASD) and the Los Angeles Police Department (LAPD). The laboratory records included various documents that informed the creation of the collection tool for this project and included key descriptive, investigative, physical evidence, and analytical tests performed on the evidence. Initially, project staff reviewed a number of case files from both the LASD and the LAPD to develop an understanding of the detail and completeness of information contained in various medical examination and laboratory documents. The objective was to find key descriptive and scientific evidence information that was common to both agencies crime laboratory files and that would describe the types of sexual assaults forming the backlog. After a preliminary review of the files, several attributes were identified that were subsequently included in the data collection tool, including case identifying information and victim medical report items.

Information collected included outsourced laboratory reports prepared by each of the private laboratories contracted by the respective agencies to examine evidence contained in the sexual assault kits as well as sexual assault kit evidence and transmittal forms between law enforcement and testing laboratories, including toxicological samples. Other information collected included Combined DNA Index System (CODIS) eligibility information, CODIS match detail reports, and local DNA Index System (LDIS) detail reports. The CODIS eligibility information identified whether DNA test results were eligible for upload into CODIS, as well as eligibility review date. The CODIS match detail report included whether the uploaded profile resulted in a CODIS match to another profile already in the CODIS system, also known as a "hit". The LDIS detail report included the uploaded loci information for CODIS and the upload date, and reported if a full or partial profile was uploaded to CODIS.

The LASD case files contained a copy of the original Office of Criminal Justice Planning (OCJP) medical report completed by medical personnel performing the sexual assault exam on the victim following the assault. The OCJP form described the age, gender and ethnicity of the victim, other self-reported information, and various examination items. The LASD crime laboratory requested that sexual assault investigators complete an audit form/questionnaire supplying certain information on each of the backlogged cases. The LAPD crime laboratory did not include copies of the OCJP form in its case files. Researchers attempted to collect the information contained on this form from other documents contained in the file, including the Serology Item Description Notes, the Request for Serology/DNA Analysis form, the Property Report, and the Investigative Report. The Serology Item Description Notes form included victim characteristics, assailant characteristics, and certain case characteristics.

Sexual assault case information was collected and coded by the research team on 2,319 sexual assault cases, including 1,948 backlogged cases and 371 non-backlogged cases. Criminal justice case disposition information was collected on a backlog disposition sample (BLDS) of 371 backlogged cases and a non-backlog disposition sample (NBLDS) of 371 non-backlogged cases. Disposition information was provided through queries to the LASD records bureau, LAPD detective division, and the Los Angeles County District Attorney's office. LAPD and LASD staff used various records/data systems to locate the needed criminal justice outcomes. Staff in those units were provided with a spreadsheet that contained the respective file numbers for cases in both NBLDS and BLDS project files, and space for recording the disposition outcomes.

Sample View help for Sample

In order to obtain a representative case sample of backlogged cases for this research project, a random sample was selected from among all 10,895 backlogged sexual assault case files of both agencies that had been submitted to an outside testing laboratory by either the Los Angeles Police Department (LAPD) or Los Angeles Sherriff's Department (LASD) laboratory. After obtaining the total list of cases in each laboratory's backlog file, the project staff took a 20 percent random sample of each list in September 2010. After obtaining this list, a small number of cases were excluded from the sample, including cases that were found on the backlog case list, but were actually determined to be non-backlogged. This was indicated if the file did not have a backlog grant sticker on the front of the file, and/or the file did not contain paperwork denoting it as a backlogged file, and/or the sexual assault kit was not outsourced to a private laboratory, and/or the sexual assault kit was processed within the year the crime occurred. Cases involving suspected juvenile offenders and cases where no external contract laboratory testing was performed were also excluded. The official number of backlogged cases fluctuated slightly throughout the duration of the project. This was due primarily to the identification of newly discovered backlogged cases that had not been counted or registered originally, as well as the elimination of certain cases not meeting the definition of a backlogged case. Therefore, the initial backlogged population from LAPD reflected 6,157 cases, while the final number the agency reported was 6,132. Similarly, the initial backlogged population obtained from LASD included 4,694 case files, while their final reported number was 4,763.

Of 6,157 LAPD backlogged cases, a 20 percent random sample yielded a sample size of 1,219 cases, from which 1,141 cases were coded. Of the 4,694 LASD backlogged cases, a 20 percent random sample yielded a sample size of 1,057 cases, from which 807 cases were coded. Thus, the 1,948 backlogged cases in the study is comprised of 1,141 LAPD backlog cases and 807 LASD backlog cases.

Data were also collected on 371 non-backlogged sexual assault cases with sexual assault kits that were tested between January 1, 2009 and August 1, 2010. Thus, the final sample of 2,319 sexual assault cases is comprised of 1,948 backlogged cases and 371 non-backlogged cases. Of the 2,319 cases in the study, criminal justice case disposition information was collected on 742 cases including a backlog disposition sample (BLDS) of 371 of the 1,948 backlogged cases and a non-backlog disposition sample (NBLDS) of 371 non-backlogged cases.

Time Method View help for Time Method

Universe View help for Universe

All sexual assault cases in Los Angeles, California, between 1982 and 2009 with backlogged sexual assault kits collected with the Los Angeles Sheriff's Department (LASD) and the Los Angeles Police Department (LAPD), and all non-backlogged LASD and LAPD sexual assault cases that were tested between January 1, 2009 and August 1, 2010.

Unit(s) of Observation View help for Unit(s) of Observation

Data Source View help for Data Source

Data Type(s) View help for Data Type(s)

Mode of Data Collection View help for Mode of Data Collection

Description of Variables View help for Description of Variables

The study contains 377 variables relating to victim, suspect, and case/crime characteristics, laboratory information and testing results, Combined DNA Index System (CODIS) information, and criminal justice dispositions of backlogged and non-backlogged sexual assault cases. The variables include general demographic information on the suspect and victim such as age and race and information pertaining to the suspect's relationship to the victim. Variables are included on the victim's use of drugs and/or alcohol. Variables relating to the use of a weapon, types of acts reported, and injuries sustained during the sexual assault are also included. Information from laboratory results include items such as where on the victim any foreign DNA was found, if it was male or female, and if there was a DNA match found. Criminal justice case disposition variables include variables pertaining to arrests, filing of charges, convictions, incarceration, and probation.

Response Rates View help for Response Rates

Not applicable.

Original Release Date View help for Original Release Date

2013-11-13

Version History View help for Version History

Weight View help for Weight

none.