Genealogy site didn’t know it was used to seek serial killer

Authorities probe the backyard of the home of murder suspect Joseph DeAngelo, Thursday, April 26, 2018, in Citrus Heights, Calif. DeAngelo, 72, was taken into custody Tuesday on suspicion of committing multiple homicides and rapes in the 1970s and 1980s in California. Authorities spent the day going through the home for evidence. (AP Photo/Rich Pedroncelli)
John Lopes, a crime scene investigator for the Sacramento Sheriff's office, carries boxes of evidence taken from the home of murder suspect Joseph DeAngelo to a sheriff's vehicle Thursday, April 26, 2018, in Citrus Heights, Calif. DeAngelo, 72, was taken into custody Tuesday on suspicion of committing multiple homicides and rapes in the 1970s and 1980s in California. Authorities spent the day going through the home for evidence. (AP Photo/Rich Pedroncelli)
In this March 1, 2018, photo, rape survivor Jane Carson-Sandler, of Sun City Hilton Head, S.C. poses for a photo holding a copy of her book about the experience called, "Frozen in Fear." Carson-Sandler was one of may victims of a California serial rapist. (Jay Karr/The Island Packet via AP)
This undated law enforcement photo provided by the Sacramento County, Calif., Sheriff's Office shows Joseph James DeAngelo. DeAngelo, a suspected California serial killer who committed at least 12 homicides and 45 rapes throughout the state in the 1970s and '80s was identified Wednesday, April 25, 2018, as a former police officer, an official said. (Sacramento County Sheriff's Office via AP)
A car is backed out of the garage of a home searched in connection with the arrest of a man on suspicion of murder, Wednesday, April 25, 2018, in Citrus Heights, Calif. The Sacramento County District Attorney's Office plans to make a major announcement in the case of a serial killer they say committed at least 12 homicides, 45 rapes and dozens of burglaries across California in the 1970's and 1980s. (AP Photo/Rich Pedroncelli)
An arrest had been made in the case of a man responsible for at least 12 killings and 50 rapes throughout California in the 1970s and 80s.
T. Abbott, left, and John Lopes, right, from the Sacramento County Sheriff's crime scene investigation office, conference about boxes of evidence gathered from the home of murder suspect Joseph DeAngelo, Thursday, April 26, 2018, in Citrus Heights, Calif. DeAngelo, 72, was taken into custod Tuesday on suspicion of committing multiple homicides and rapes in the 1970s and 1980s in California. Authorities spent the day going through the home for evidence. (AP Photo/Rich Pedroncelli)

SACRAMENTO, Calif. — A genealogy website that investigators used to find the former police officer they believe was one of California’s most terrifying serial killers had no idea its services were being used to pursue a suspect who eluded law enforcement for four decades.