“Cold case” murders are being solved at a record pace—and all the suspects are white men.

What’s happening: Investigators are entering genetic evidence from old, unsolved rape-murders into a publicly accessible database of DNA profiles. Genealogists can then use genetic matches to distant family to locate the probable suspect. The sleuthing combines DNA, birth records, and social-media profiles.

What’s new: Since the first cold case was broken in April, the floodgates have opened. Genetic genealogy has pointed to a suspect in four more cases, including two this week. Here’s the list so far:

April 25—Police arrested Joseph James DeAngelo for being California’s notorious Golden State Killer.

May 18—Truck driver William Talbott arrested for a 30-year-old double murder in Washington State.

June 22—Gary Hartman arrested for the murder of a 12-year-old in Tacoma, Washington, in 1986.

June 25—James Otto Earhart named as the suspect in the killing of real estate agent Virginia Freeman. Earhart was put to death in 1999 for a different crime.

June 25—Police arrest Raymond “DJ Freez” Rowe in the killing of a Pennsylvania school teacher 25 years ago.

Super sleuth: The genealogist behind the last four cases is CeCe Moore (pictured, above), whom MIT Technology Review profiled last week.

Only white men? According to Moore, genealogy databases mostly reflect people of Northern European ancestry. Killers with similar roots are the ones that can most easily be found this way.