January 20, 2022
Final Reports
San Mateo Courts - Civil Grand Jury

2002-2003 Report:

Handling Sexual Assault Cases

Summary | Background | Findings | Conclusions | Recommendations| Response


The Grand Jury inquired how the District Attorney’s (DA) Office determines when to prosecute sexual assault cases, and how many such cases are prosecuted annually. The DA’s Office was unable to provide meaningful statistics regarding the number of all rape cases it handled for the last five years with the final dispositions (guilty, acquitted, dismissed, etc.).

The Grand Jury gathered data demonstrating that instances of rape steadily increased in the last five years in San Mateo County; fewer cases were submitted to the District Attorney’s Office by law enforcement; and in the last two years the DA’s Office declined to prosecute half of the cases received, but it’s conviction rate for those cases prosecuted is approximately 90%.

The DA must be certain it can demonstrate guilt beyond a reasonable doubt before a case is pursued. The Grand Jury was told that how well a victim will come across in court often makes a difference whether a case is prosecuted or not. The District Attorney’s Office cannot assure each victim of sexual assault that the crime perpetrated against them will be prosecuted. The victim’s cooperation and ability to produce timely physical evidence, be convincing, or have corroboration of the circumstances of the incident, is a major factor in determining to prosecute.

Issue: Do San Mateo County law enforcement agencies and the District Attorney’s Office handle sexual assault cases in a manner that vigorously pursues criminal justice for all involved parties?


During the Grand Jury investigation of how forensic evidence is handled in San Mateo County, the volume of rape cases reported by each law enforcement agency in the county for the last five years, and handled by the District Attorney’s Office for years 2000 and 2001, was obtained. Interviews with the District Attorney’s Office, the Sheriff’s Office, and several police chiefs and their staffs provided considerable information regarding how biological evidence is obtained, stored, and sometimes tested in sexual assault cases. Details were provided regarding how decisions are made to file charges and prosecute such crimes.

The information obtained provided findings not directly related to the forensic evidence investigation, so the Grand Jury has prepared this separate report of findings and recommendations associated with the handling of sexual assault cases in the county.


The Grand Jury asked the District Attorney’s Office (DA) to provide the number of all rape cases prosecuted by year for the last five years, with the final dispositions (guilty, acquitted, dismissed, etc.). The DA obtained data from court records by branch, but because of the fee to retrieve the data, only information from 2000 and 2001 was retrieved. This data was not reliable because cases overlapped in each court branch and over calendar years. The DA does not track all of its cases by type of case and final disposition. In February 2000 the Deputy District Attorney – Sexual Assault Unit began a log of sexual assault cases and provided the Grand Jury that data through 2001.

San Mateo County Rape Cases Reported by Law Enforcement
and Handled by the District Attorney's Office
# Police Cases
# Cases Received by DA
% Police Cases Sent to DA
# Cases DA Declined to Prosecute
% DA Declined to Prosecute
# Cases DA Convicted
% Cases Tried by DA with Convictions
% Change
* February through December

The District Attorney’s Office stated that it determines whether to proceed with a prosecution based on an evaluation of witnesses and evidence. Within 48 hours of an arrest and prior to charges being filed, or prior to police making an arrest, the DA interviews the victim to see if the victim is convincing, reliable, and if there is other evidence. The victim’s ability to be consistent and credible, and their willingness to participate in the judicial process, are considered necessary in order for the DA to proceed. The DA stated that in many cases how well a victim will come across in court makes the difference whether a case is prosecuted or not. The DA also stated that victims who were intoxicated or on drugs at the time of the assault, and who could not accurately remember details of the assault, are not likely to be credible to a jury. In such cases the DA needs witnesses that can corroborate the victim’s story or evidence of physical injury to build a provable case. There are numerous factors to be considered when determining a victim’s willingness and ability to provide timely physical evidence and be consistent and credible in describing the assault. The DA wants to be certain it can demonstrate guilt beyond a reasonable doubt before a case is pursued.


While instances of rape increased in San Mateo County, fewer cases were submitted to the District Attorney’s Office by law enforcement agencies, and the District Attorney’s Office declined to prosecute a larger percentage of cases submitted. Those cases prosecuted have an admirable conviction rate of 87 - 90%. However, 23 months of data provided by the DA is insufficient to conclude there is a trend. Review of the available data generates numerous questions that could not be pursued within the scope of the original investigation (e.g., Why are fewer cases being submitted by law enforcement to the DA? Why does the DA’s Office decline to prosecute half the sexual assault cases it receives?). Further review at this time is hampered by limitations of the data provided by the District Attorney’s Office.

The process to obtain information from the District Attorney’s Office regarding the number of cases handled, current status, and eventual disposition is cumbersome and expensive, and the mechanized data provided is not straightforward. The DA is unable to provide meaningful statistics regarding the volume of its annual caseload by type of case and by disposition. With the level of technology available today it is not unreasonable to expect that the San Mateo County District Attorney’s Office would have its own database and management information system to track productivity, caseload, and disposition of cases.


  1. The District Attorney's Office must develop a management information system that tracks all cases, productivity, and final dispositions. The system should also aid in case assignment, management of individual caseloads, and provide current status of cases in progress. It should also allow analysis of trends by type of case and rate of prosecution for each. Until a comprehensive system can be installed, the DA should immediately develop a tracking process for each type or category of case handled, similar to the one the Deputy DA currently uses for sexual assault cases.

  2. In 2003-2004 the Grand Jury should investigate the process of how sexual assault cases are investigated and prosecuted in San Mateo County.

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