Melvin Turner, a death row inmate at the San Quentin Rehabilitation Center, died over the weekend, prison officials said Wednesday.

The California Department of Corrections and Rehabilitation (CDCR) said Turner was pronounced dead at 6:04 p.m. Saturday. He was 67. There were no further details on the cause of his death.

Turner was convicted of the 1979 execution-style slayings of 35-year-old Dr. Joseph Hill and 44-year-old teacher Joella Champion in an airport hangar in Torrance, Los Angeles County. Prosecutors said Turner and an accomplice were at the airport to steal Hill's sports car, and Turner shot both victims in the head as they were bound and gagged on the floor.