Lynn Penn, a 60-year-old man, was found strangled inside his apartment in the Westlake area of Los Angeles in July 1990. The killing offered investigators few immediate answers, and the case remained unsolved for more than two decades. Among the evidence recovered from Penn's apartment was a cigarette butt. Although it could not identify his killer at the time, saliva left on that cigarette eventually became the crucial piece of evidence that would reveal who had been inside the apartment.
For years, Penn's homicide remained separate from a series of strangulation murders committed by Juan Chavez in Los Angeles County during the 1980s. Chavez had targeted middle-aged men whom he encountered around Los Angeles and then accompanied to their homes. According to investigators and court records from the cases for which he was prosecuted, Chavez commonly threatened the men, restrained them and strangled them before stealing money, bank cards, jewelry, electronics or vehicles. Chavez gave statements suggesting hostility toward gay men and claimed he wanted to stop the spread of AIDS, although prosecutors believed robbery was an important underlying motive for the murders.
Chavez was already imprisoned by the time investigators developed the cases against him. In 1992, he was convicted in Merced County of kidnapping for ransom and received a life sentence plus an additional 28 years. Los Angeles investigators eventually connected him with five earlier killings after evidence from the 1986 murder of Alfred Rowswell led them back to Chavez. A photograph showing someone using a victim's ATM card also became important evidence. Chavez made incriminating statements and confessed while being interviewed in prison. In 1994 he was charged with five murders and five robberies. His murder case proceeded for several years, and in March 1999, during his trial, Chavez pleaded guilty to murdering the five men in exchange for prosecutors agreeing not to seek the death penalty. He was subsequently sentenced to five life terms without the possibility of parole.
Penn's name was not among those five murder convictions. His killing was still officially unresolved when Chavez died. On September 9, 1999, Chavez hanged himself in his cell at Folsom State Prison. Because Penn's murder had never been connected to him while he was alive, there was no arrest, murder charge, trial or conviction of Chavez specifically for Penn's death.
The breakthrough came years later through a California initiative designed to obtain DNA profiles from convicted offenders who had died before their genetic information had been entered into modern criminal databases. Investigators discovered that blood taken during Chavez's autopsy was still preserved. A DNA profile was developed from that material and entered into California's criminal DNA databank. In 2012, authorities obtained a match between Chavez's genetic profile and DNA recovered from the cigarette butt left inside Penn's apartment. The evidence finally connected Chavez directly to the scene of Penn's strangulation approximately 22 years after the murder.
The DNA identification effectively solved Lynn Penn's homicide, but it came too late for a prosecution. Chavez had already been dead for nearly 13 years when investigators established the connection. The discovery nevertheless answered the central question that had remained unresolved since Penn was found in his apartment: the physical evidence left behind by his killer identified Juan Chavez as the man responsible for his death. Penn's case became an early demonstration of how preserved evidence and DNA from deceased offenders could close murders that had remained unsolved for decades, even when the perpetrator could no longer be brought before a court.
