SUNNYSIDE, Wash. — A woman has been arrested in connection with the killing of a 23-year-old Sunnyside man, the Yakima County Sheriff’s Office said Sunday.

Sheriff’s detectives arrested the 20-year-old woman Saturday night on suspicion of second-degree murder after phone records and other factors pointed to her as a suspect. A sheriff’s office news release did not name the woman, but it said other suspects are being sought.

Alberto Gabriel Martinez’s body was found Friday afternoon in the trunk of a green 1998 Honda Civic that belongs to his girlfriend, according to the sheriff’s office. The sheriff’s office did not identify the girlfriend Saturday in its initial report of the crime, nor did it say Sunday whether the woman arrested is the girlfriend.

The sheriff’s office spokesman, Chief of Detectives Stew Graham, could not be reached for comment Sunday.

The car was located by Yakama Nation police south of Toppenish on Oak Springs Road off U.S. Highway 97, near milepost 51. Tribal police turned the case over to the sheriff’s office.

A cause of death has not yet been determined, though an autopsy has been scheduled for today.

Martinez was last seen Thursday night, according to the sheriff’s office. Anyone with information about the case is asked to call the sheriff’s office at 509-574-2500, or Crime Stoppers Yakima County, 800-222-TIPS.