SAN DIEGO -- A 57-year-old man was arrested Tuesday on suspicion of killing his wife in October and his first wife in 1973, authorities said.

William New is being held at the Sheriff's Central Detention Facility without bail after being arrested about 4:15 p.m. on suspicion of murdering 58-year-old Phyllis New in October and his first wife, 29-year-old Somsri New in 1973, Capt. Glenn Revell of the San Diego County Sheriff's Department said. He will be arrainged Thursday in El Cajon.

An arrest warrant had been issued in San Diego County Superior Court Monday, Revell said.

William New called the sheriff's communication center about 4 a.m. on Oct. 15 to report that an unknown person broke into his home at 9255 Magnolia Ave. in Santee and injured his wife, Revell said.

Sheriff's deputies and personnel from the Santee Fire Department arrived and declared Phyllis New dead about 4:10 a.m., Revell said, adding that an autopsy revealed she died as the result of a gunshot wound, consistent with a homicide.

Detective Pat Gardner led an 18-week investigation into the homicide that included experts from the sheriff's crime laboratory. They learned that New's first wife, Somsri, also died of a gunshot wound. The incident occurred in the New's home at 1217 West Belleview St. in San Bernardino on Sept. 9, 1973, Revell said.

Investigators originally believed Somsri New's death to be an accident, Revell said.

Deputy District Attorney Jill Drain assisted investigators throughout the investigation.

"Her expertise is instrumental in our quest to prosecute New for the murder of both wives," Revell said.

Anyone with information about either death was asked to contact Detective Pat Gardner at (858) 974-2321.