1990s

The 1990s were a hinge in forensic investigation: DNA evidence moved from a laborious, fragile laboratory procedure toward faster testing and database comparisons capable of reopening cold cases. In Orange County, the decade’s change became concrete in 1996, when a database match identified a serial killer and freed a man wrongly imprisoned for sixteen years; months later, a new testing method helped investigators connect three murders that had not previously been treated as linked.

From slow testing to faster profiles

At the beginning of the decade, DNA testing was still demanding. When the Orange County Crime Lab began incorporating it in the early 1990s, a criminalist could spend as long as four weeks working a single case. The sample had to be substantial and in good condition: a bloodstain about the size of a quarter offered the kind of material the process required. By contrast, later techniques could produce a genetic profile from a small scattering of skin cells in hours. The difference was not merely convenience; it widened the range of evidence that could be tested and made old, limited, or degraded samples more useful.

The method used in early database work, RFLP analysis, required ample, undegraded DNA and was slow enough to become a bottleneck. A newer approach adopted by the Orange County Crime Lab in 1996, PCR-STR, was faster and suited to the small or time-damaged samples common in cold cases. The book compares the older method to copying figures by hand and the newer one to using a high-speed copier. That shift mattered especially for evidence already stored away: time had not necessarily erased its value, but the laboratory needed a method capable of recovering information from it.

Databases and the first cold hit

The DNA Identification Act of 1994 established the Federal Bureau of Investigation’s authority to maintain a national database, creating the basis for CODIS. The later system is described as a layered network: local laboratories enter unknown crime-scene profiles and eligible suspect samples into state databases; state systems verify and compare them before forwarding profiles to the national level. The account also notes that California samples are automatically uploaded each Tuesday and that states collect DNA in jails and courthouses. This architecture helps explain how an individual laboratory result could become part of a much wider search, although the national database was still developing during the decade.

In December 1995, Orange County prosecutors, detectives, and criminalists began submitting evidence from old unsolved cases to a new California Department of Justice laboratory in Berkeley. Its files held four thousand profiles from known violent offenders, many of them sex offenders. The state database was young, and Orange County’s submissions helped build it. The county’s first cold hit came six months later, in June 1996: crime-scene DNA matched that of Gerald Parker, an inmate who was identified as the serial killer of five women.

The match also corrected a grave injustice. A sixth victim, who was pregnant, survived an attack, but her full-term fetus did not. Her husband had suffered severe memory loss from his injuries and had spent sixteen years in prison for the assault. The DNA result exonerated him. Parker, meanwhile, was about a month from release when the match was made. The first successful database search did not simply attach a name to old evidence; it altered the fate of a living person while identifying a serial offender.

Reopening the unsolved cases

The Parker identification changed how the Orange County Sheriff’s Department and crime-lab staff regarded evidence that had sat for years in the Property Room. A strategy for reviewing cold cases followed. From 1972 through 1994, Orange County had investigated 2,479 homicides and cleared 1,591, leaving nearly 900 unsolved. Cases involving sexual assault were given priority because repeat offenders were more likely to leave biological evidence suitable for DNA typing. The aim was not limited to finding an immediate match in a database: profiles from separate cases could also be compared with one another, potentially revealing a series and giving investigators a new direction.

Criminalist Mary Hong was assigned to work on cold cases. Jim White, who had long suspected a connection between the murders of Keith and Patty Harrington and Manuela Witthuhn, urged her to prioritize those cases. Hong had not worked in the laboratory when the murders occurred, so White’s suspicion supplied a lead rather than a conclusion. In late 1996, she retrieved the rape kits and used the laboratory’s newly integrated PCR-STR process, which was particularly useful when evidence was scant or degraded.

A few weeks later, as the year ended, Hong reviewed a spreadsheet containing about twenty unsolved cases with successfully developed DNA profiles. The chart cross-referenced case numbers and victims with results at five PCR markers, or loci. She already knew the Harrington and Witthuhn profiles matched. While scanning the other entries, she noticed that another profile matched as well. It belonged to Janelle Cruz, whose body had been found in her family’s Irvine home on May 5, 1986. No one had previously proposed that her murder was connected to the other two.

The match joined cases that seemed different in important respects, including the victims’ ages and the more-than-five-year span between the crimes. Yet Cruz lived in Northwood, the same subdivision as Witthuhn, and their homes were only two miles apart. The shared profile turned those details into a reason to reconsider the cases together. By the close of the decade, DNA had moved beyond identifying a known offender in a database: comparison among cold-case profiles could expose a connection investigators had not already suspected.

The promise and its later limits

The decade’s progress depended on several systems working together: preserved evidence, laboratory methods capable of extracting a profile, and databases containing samples against which it could be compared. Each stage had limits. Early RFLP testing demanded larger, better-preserved material; a database match depended on a relevant profile being present; and a profile developed from one case could prove useful even when no known offender appeared in the files. The Orange County review therefore combined laboratory technology with deliberate case selection and comparison across files.

Later discussions in the book extend that history to commercial genealogy databases. 23andMe and Ancestry.com held far larger collections of profiles, but the companies would not work with law enforcement, citing privacy and their terms of service. The prospect of using relatives’ profiles to direct a search raised further concerns, including the Fourth Amendment. Those later debates were not the same as the 1990s database-building effort, but they sharpen its legacy: expanded genetic comparison can create investigative leads, while the institutions and rules governing access determine which searches can be made.