Gypsy Hill killings: Elderly sex offender convicted of 1976 murder of Daly City woman

Leon Melvin Seymour was convicted of the 1976 murder of 19-year-old Dinese Lampe, closing one of the long-standing cases of the "Gypsy Hill Killings."

DALY CITY – A man already in prison for violent sexual crimes was convicted Friday in the slaying of a 19-year-old Peninsula woman that was part of the gruesome “Gypsy Hill Killings,” officially closing a case that took nearly half a century.

Leon Melvin Seymour, 77, who has been in custody as an inmate-patient at Coalinga State Hospital for kidnapping and sexual assault convictions dating back to the 1970s, was officially convicted Friday after an 18-day trial. Seymour, who is housed as a sexually violent predator, was kept in custody at San Mateo County Medical Center during the trial.

He was deemed responsible for the April 1976 stabbing death of 19-year-old Denise Lampe, who was found dead inside her car in the parking lot of the Macy’s at Serramonte Mall, where she worked. She was supposed to meet a friend after her shift, but never arrived.

Law enforcement officials do not believe Lampe and Seymour knew each other.

Rodney Lynn Halbower, who has been in Oregon prison for most of his adult life, was later convicted of two of those killings and received more prison time in 2018. It was long thought that the five killings were performed by the same person, but Seymour’s 2017 arrest demonstrated that investigators had formed new theories.

According to the San Mateo County Office of the District Attorney, the case was reinvigorated nearly 40 years after the killing when investigators went back to test a DNA sample to see if it could be linked to another suspect. A blood stain on Lampe’s jean jacket was traced back to Seymour, who was already in prison for previous convictions.

The District Attorney’s Office did not immediately respond to a request for comment.