Chase Darkness With Me

Billy Jensen grew up on Long Island in the late 1970s, absorbing crime stories from his father, William, a former juvenile delinquent turned house-painting contractor. In 1977, five-year-old Jensen watched his father unfurl the front page of Newsday announcing the capture of David Berkowitz, the serial killer known as Son of Sam. The wave of relief that swept through their household left a lasting impression: order restored from chaos. That feeling became the driving force behind Jensen's career.

William shaped his son in other ways. At bedtime, he told his own life story in installments: running away from home at 15 under a stolen identity, punching an off-duty detective, and being sent to a youth reformatory after police published his photo in Newsday under the headline "DO YOU KNOW THIS MAN?" The two became inseparable, and William wove cautionary tales about local murders into their evenings together.

After studying mythology at Boston University and cults at the University of Kansas, Jensen returned to Long Island when his father needed open-heart surgery. William recovered but was later diagnosed with hepatitis C, likely contracted from sharing needles during a past heroin addiction. He died on April 23, 1998. Jensen describes the loss as a "rip-off": His father invested everything in shaping him but would never see the results.

Jensen had begun freelancing for the New York Times. In 1999, he covered his first murder: a mummified pregnant woman found inside a barrel in the crawl space of a Long Island home. Jensen called the original homeowner, Howard Elkins, who claimed ignorance. Six days later, detectives visited Elkins in Florida; shortly afterward, Elkins killed himself with a shotgun. The victim was identified as Reyna Angélica Marroquín, an El Salvadoran immigrant who had had an affair with Elkins and told his wife; her address book contained the faded words "Don't be mad I told the truth." A subsequent New York Post assignment, in which editors pressured Jensen to re-approach a grieving family, left him ashamed and clarified his purpose: He would only write about unsolved crimes.

Over the following years, Jensen investigated cold cases for the Long Island Press in a section called "Long Island Confidential." He pursued the 2001 murder of Henryk Siwiak, a Polish immigrant shot in Brooklyn on September 11 while lost on his way to a cleaning job, making Siwiak the only other murder victim in New York City that day. He also reported on Brian Boothe, found dead in his Manhattan apartment with a knife wound police classified as a suicide; Jensen's reporting helped reclassify the death as a homicide, but the trail had gone cold. Letters from victims' families began arriving, asking for help.

In 2013, Jensen moved to Los Angeles to develop a television show about solving cold cases. There he met Michelle McNamara, a true-crime writer hunting a long-unsolved serial predator in California. The attacker had operated under separate names in Northern and Southern California for decades; Michelle rebranded him the "Golden State Killer." The two became close collaborators, co-hosting a live-streamed show and presenting a panel on crowdsourcing investigations at the South by Southwest conference. Michelle's husband was comedian Patton Oswalt.

In April 2016, Jensen traveled to New Hampshire to investigate the Allenstown Four: a woman and three young girls whose remains were found in two barrels in Bear Brook State Park, the first pair discovered in 1985 and the second in 2000. None had been identified. That same evening, Jensen checked his phone in a Boston bar and learned that Michelle had died in her sleep at 46.

Grief and frustration converged. Weeks later, Jensen watched surveillance footage of the murder of Marques Gaines, who was punched unconscious by a large man in a green hoodie outside a Chicago 7-Eleven, robbed by passersby, and then run over by a taxicab. Jensen spotted a distinctive widow's peak beneath the attacker's hood and tested a new approach. He created a Facebook page, wrote a post in the attacker's voice, and paid to display it to users within two miles of the crime scene. A sports blogger's retweet on Twitter produced a clear photo of the attacker. After combing through thousands of mugshots, Jensen identified Marcus Moore and flew to Chicago to confirm the identification. He delivered a dossier to detectives and spent months pressuring police to act. In January 2017, Moore was arrested in Minnesota. The victory was bittersweet: Neither Jensen's father nor Michelle was alive to share his first solve in 17 years.

Jensen threw himself into a punishing routine, running social media campaigns for dozens of cases while editing Michelle's manuscript for I'll Be Gone in the Dark. With researcher Paul Haynes, he structured the book and wrote a final section on the methods Michelle believed would catch the killer: geographic profiling, which uses crime locations to infer where an offender lives, and familial DNA matching, which identifies suspects through genetic relatives in public databases. Among Michelle's files, Jensen discovered a letter addressed to the killer, warning him that "virtual windows are opening all around you."

Jensen's campaigns produced mixed results. In Nashville, geotargeted ads helped flush out the final suspect in the murder of French fashion designer Teddy Grasset. In El Monte, California, Jensen identified the mask and getaway car used in the shooting of pharmacy technician Juan Vidal; a tipster led police to 20-year-old Louie Herrera, and the detective publicly credited Jensen's Facebook page. Other cases stalled. Jensen poured over $1,000 into finding the killer of Jennifer Cohen in Brooklyn's Owl's Head Park but received no leads. When Cohen's son commented on the post, "That was my mom," the case became Jensen's white whale.

Meanwhile, the Allenstown Four investigation broke open through familial DNA testing, which linked the victims to a serial murderer who had used at least four aliases across the country. His true name was Terrence "Terry" Peder Rasmussen. Jensen and retired detective Pete Headley began building a timeline of Rasmussen's movements to identify additional victims.

On the night of April 24, 2018, Jensen was in a Chicago hotel after a book event for I'll Be Gone in the Dark. At 2:00 a.m., he learned a suspect in the Golden State Killer case was in custody. Jensen found a 1979 article about Joseph James DeAngelo, a former police officer fired for shoplifting dog repellent and a hammer. At 4:30 a.m., he texted Patton: "She got him." Paul Holes, an investigator from the Contra Costa County district attorney's office, later explained the arrest: Investigators entered a full genome DNA profile into GEDmatch, a public database where users upload genetic data to find relatives, traced a third cousin's family tree to DeAngelo, and confirmed the match with a tissue from his trash. Jensen notes that the technique traced back to Headley's work on the Allenstown case. In the days that followed, Jensen's inbox filled with messages from forensics investigators, engineers, and volunteers offering to help solve cold cases.

In June 2019, the Allenstown victims were finally identified, thanks to citizen detective Becky Heath, a financial services librarian who connected a 1999 message board post to the case. The woman in the barrel was Marlyse Honeychurch, last seen leaving a family gathering with Rasmussen around 1978. Two of the children were her daughters, Marie Elizabeth Vaughn and Sarah McWaters. The family placed four small crosses at the Bear Brook site, naming the fourth, still-unidentified child "Angel."

In the epilogue, Jensen searches through old Newsday archives and finds the article his father described during those bedtime stories: a photograph of his young father under the headline "DO YOU KNOW THIS MAN?" Jensen prints the article and hangs it on his wall alongside the photos of the suspects he is still chasing.