KEY LARGO, Fla. — More than five decades after two New Jersey sisters were killed in the Florida Keys, authorities have identified a suspect in the long-unsolved case through advances in DNA technology and genetic genealogy, Monroe County Sheriff’s Office officials announced Wednesday.
MCSO Sheriff Rick Ramsay said major crimes detectives, working with the Florida Department of Law Enforcement, identified David Allen Snyder, formerly of Key West, as the man responsible for the 1973 killings of sisters Marguerite “Maggie” Jenkins, 18, and Mary Jenkins, 16.
He said Snyder died of natural causes Oct. 28, 2008, in Mountain View, Idaho. He was 57.
The sisters had traveled from New Jersey to the Florida Keys for vacation in April 1973. according to Ramsay.
Investigators said they were last seen hitchhiking on Stock Island on May 2, 1973. The next day, a resident discovered their bodies in a wooded area about 100 yards from U.S. 1 near Mile Marker 99.5, according to Ramsay.
Investigators determined the sisters had been severely beaten and appeared to have suffered gunshot wounds. The case remained unsolved for decades, with investigators unable to identify a suspect.
A breakthrough came years later as investigators revisited evidence using newer forensic technology.
In 2018, sheriff’s detectives and FDLE developed additional markers from a partial male DNA profile recovered from a bloodstain on one of the victims’ underwear, according to Ramsay.
Ramsay said updated profile was entered into a national DNA database, but it did not produce a match at the time.
Authorities said FDLE investigators continued working the case and in 2023 began using genetic genealogy and family-tree research alongside DNA databases. That work eventually pointed investigators toward Snyder.
Earlier this year, authorities obtained a DNA sample from one of Snyder’s relatives and submitted it to the FDLE crime laboratory for testing. The laboratory results confirmed Snyder as the source of the DNA profile, according to MCSO officials.
Investigators also determined that Snyder lived in several locations in Key West between 1972 and 1974, placing him in the area around the time of the killings.
Ramsay credited the investigators and FDLE with pursuing the case despite the passage of more than 50 years.
“I want to thank the Detectives of our Major Crimes Division for their hard work alongside the FDLE in bringing closure to the family of these two victims,” Ramsay said in a statement. “This case highlights the importance of our law enforcement partnership with the FDLE and our commitment to solving crimes no matter how long it may take.”
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