State DNA Data Bank Has Linked Thousands of Crimes to Violent Criminals

Thursday, April 8, 2010
Contact: (916) 210-6000,

Los Angeles—Attorney General Edmund G. Brown Jr. announced today that the state DNA Data Bank has now matched 12,000 crime scene DNA samples to violent offenders and other suspects, helping to “secure thousands of convictions” of rapists, murderers, and kidnappers.

The DNA Data Bank’s 12,000th match was made at the state DNA database facility in Richmond. On average, the DNA Data Bank receives 300 hits per month. In March, the Data Bank had 405 DNA matches, the most ever in a single month.

“This is a remarkable milestone in the advancement of criminal justice technology,” Brown said. “The DNA database has been used in over 12,000 investigations and contributed to thousands of convictions of the most violent criminals. Otherwise, these crimes are likely to go unsolved.”

Recent notable cases in which the California Department of Justice assisted local law enforcement in the apprehension of dangerous sexually violent predators through DNA evidence include:

• In February, John Gardner III, a convicted sex offender, was arrested on suspicion of rape and homicide in the disappearance of Chelsea King, a 17-year-old high school student from San Diego County who went jogging in a park. She was found in a shallow grave in the park.
• In January, David Joseph Carpenter, a Death Row inmate also known as the “Trailside Killer”, was linked by DNA evidence to the killing of Mary Bennet, who was stabbed to death in San Francisco. The crime occurred in 1979. (Additional cases are listed below.)

The DNA Data Bank has been in operation since 1994 and contains over 1.5 million DNA samples. Approximately 25,000 samples are added to the database each month.

A voter-approved initiative in 2004, Proposition 69, required all defendants convicted of a felony to submit a DNA sample. On January 1, 2009, this requirement was extended to all adults arrested on felony charges.

In criminal investigations each day, state and local law enforcement agencies submit evidence from crime scenes to one of California’s seven Department of Justice crime labs or 15 local labs with forensic DNA capability. These labs try to establish DNA profiles to identify the perpetrators.

The DNA profiles then are uploaded to California’s database and sent to the national Combined DNA Index System (CODIS), which indexes samples for searching in categories such as convicted offenders, arrestees, crime scene samples, missing persons, relatives of missing persons, and unidentified human remains. DNA from convicted offenders and arrestees is compared with crime scene samples, and crime scene samples are compared to link cases together.


In September 2009, Richard Ramirez, a Death Row inmate known as the “Night Stalker”, was linked to yet another crime: the 1984 killing of a 9-year-old San Francisco girl, Mei Leung, after San Francisco Police Department criminalists reprocessed old evidence in the case to obtain DNA.

In August 2009, a 34-year-old cold case was solved when Dennis Vasquez, 50, of Los Angeles, was arrested and required to submit a DNA sample to authorities. Vasquez’s DNA matched the DNA found at a murder scene in 1975. He is being prosecuted for murder by the Los Angeles District Attorney’s Office.

In March 2009, Ryan Nigel Curtis, 27, of Los Angeles, was arrested for stabbing a man after an argument in Huntington Beach. Curtis’ DNA was obtained from a cigarette pack he left before fleeing.

In May 2008, Alberto Pablo Ruiz, 25, of San Jose, was sentenced to 41 years in prison after he assaulted a female jogger in Alum Rock Park in San Jose. The San Jose Police Department linked Ruiz through DNA evidence found on the victim and at the crime scene. Ruiz’s DNA had been submitted to the database for previous violations.

In March 2008, James Dixon, 37, of Pomona, was sentenced to death after his DNA matched DNA found at a 2001 murder scene in Los Angeles County. The Los Angeles County Sheriff’s office obtained DNA from a cigar tip found in the truck where the victim was murdered. Dixon’s DNA also matched that found in a 1996 home invasion in which two females were raped. The accomplice in the 1996 home invasion and rape had been sentenced to 70 years to life.

In 2001, a woman’s body was found near Mussel Shoals beach in Ventura County. The Ventura County Sheriff’s Office collected DNA and uploaded it into the national DNA database. The sample matched Douglas Dworak, 43, of Oakview, a convicted rapist who had been sentenced to death in 2005.

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