A cold case just went even colder – but one Los Angeles County homicide investigator is hoping it will heat up again.

Sgt. Brian Schoonmaker of the Sheriff’s Homicide Bureau said Tuesday night that a new study of DNA evidence has cleared the prime suspects in a 33-year-old Acton murder case.

Analysts in the sheriff’s crime lab have been working overtime lately – in fact, the department recently received another $1.2 million federal grant to pay for overtime – to get their backlogged cases off the books. Some of those cases involve unsolved crimes where evidence was collected long before DNA could link, or in some instances unlink, suspects and crimes.

Such is the case of Leslie Long, a 20-year-old Palmdale resident whose body was found Dec. 8, 1978, at the base of a small hill off the 14 Freeway at Soledad Canyon Road in Acton, three days after she went missing.

According to Schoonmaker, the mother of three small children was working the evening shift at a Chevron station at Palmdale Boulevard and Division Street (now Alliance Gas) when somebody robbed the gas station floor safe and kidnapped her at gunpoint.

Sheriffs arrived shortly after 9:30 that Sunday night to find the safe open and coins scattered on the ground. They found Long’s purse in the office and her car in the parking lot. A manhunt ensued.

Sheriff’s Aero Bureau pilots spotted her body the following Wednesday. They determined she had been raped, shot and killed at the Acton location.

The media coverage was intense, Schoonmaker said. Deputies determined that at least two suspects were involved, maybe more.

Investigators eventually learned that two convicts escaped from a northern California prison just three days prior to the murder.

“There were circumstances that seemed to link the prison escapees with the Long murder,” Schoonmaker said.

He said the escaped prisoners were soon recaptured. There wasn’t enough evidence to charge them with the murder, but “it was strongly believed they were involved,” Schoonmaker said. “This is the last impression that was left with the general public.”

The investigation went cold.

“Recently, with DNA technology, both prison escapees were excluded from the trace evidence found at the crime scene,” Schoonmaker said in a statement Tuesday. “They are no longer suspects and this case remains open and unsolved.”

There is a $26,000 reward – $20,000 that the Board of Supervisors authorized Tuesday on a motion from county Mayor Mike Antonovich, together with $5,000 from Chevron Corp. and $1,000 from the city of Palmdale – for information leading to the arrest of the suspects. Call Schoonmaker directly at 323-890-5579 or to report a tip anonymously, call Crime Stoppers at 1-800-222-TIPS (8477).

To publicize the incident – and the reward – in hopes of witnesses stepping forward, the Sheriff’s Homicide Bureau has partnered with producers of the television program, “Crime Stoppers Case Files,” to produce a reenactment of the crime. The episode will be televised Sunday, Oct. 9, at 11 p.m. on KCAL-9 in the greater Los Angeles area.