Bob Crane's murder remains unsolved, four decades later

WARNING: This story contains graphic subject matter. Discretion is advised.

Friday marks 40 years since the most sensational celebrity murder in Arizona history: the murder of actor Bob Crane.

The star of "Hogan's Heroes" was bludgeoned to death while he slept in his Scottsdale apartment, and no one ever went to prison for the crime. It remains one of the top unsolved murders in American history.

Physical evidence from Crane's murder has since been packed into boxes, including Crane's blood, Crane's fingerprints, and fingerprints from the suspected killer, John Carpenter. There were also endless cassette tapes of witness interviews, Crane's homemade porn tapes, photographs of his day planner stained with his own blood, recovered from his bedside table.

These are personal items from a star's life that was dramatically cut short, and pieces of a tantalizing case that has captured the nation's imagination for 40 years.

"During my career, I've had a lot of big cases, but the Bob Crane case takes them all," said Former Maricopa County Attorney Rick Romley.

Crane defined TV's leading man in the 1960's, and still does today in endless re-runs. In the summer of 1978, Crane was starring in "Beginners Luck" at the Windmill Dinner Theater in Scottsdale when his luck ran out in the early morning hours of June 29.

Someone bludgeoned Crane to death while he slept in his apartment. There was no struggle. No sign of forced entry.

FOX 10 has uncovered graphic, never-before-seen police video taken inside Crane's apartment, as the medical examiner shaved Crane's battered head for a closer look at the fatal wounds. In the graphic video, an electrical cord, cut from a video camera, was seen tied around crane's neck. Suspicions quickly turned to Crane's longtime pal John cCarpenter, who was hanging out with Crane in hours before the murder.

The two shared a dark obsession: videotaping their sexual conquests with countless women.

"This All-American image of him, of my dad as Colonel Hogan has the dark side," said Crane's son, Bob Crane, Jr. "Colonel Hogan isn't who we thought he was. It became kind of a hobby that went too far. I think their friendship revolved around electronics and women."

Carpenter became the lead suspect when blood was discovered in his rental car one day after the murder. The blood matched Crane's rare blood type. Police theorized Carpenter killed Crane, because Crane was trying to severe their relationship.

"Towards the end of his life, my dad was definitely pulling away from John Carpenter," said Crane, Jr.

Retired Scottsdale Detective Dennis Borkenhagen interviewed Carpenter.

"He was very stoic the first time I interviewed him," Borkenhagen recounted. "First time I talked to him, I knew we were dealing with a guy that was going to be very hard to crack."

Detectives tried to get Carpenter to confess, but Carpenter never cracked. 16 years would pass before he was eventually put on trial for Crane's murder. In 1990, Rick Romley, then the new Maricopa County Attorney, reopened the Crane murder case. Investigators started from scratch.

"We re-interviewed everyone involved in this case. We tracked down each and every person," said Barry Vassall, a former homicide investigator with the Scottsdale Police Department. "We just basically eliminated everybody else on the planet."

And once again - one name. One suspect emerged. 16 years had passed, and investigators still lacked hard physical evidence tying Carpenter to the murder. DNA tests on the blood found in Carpenter's car were inconclusive, and there was no way to prove the blood came from bob crane.

"That was a big deal," said Michael Lake, who was the jury foreman in the case. "If we had DNA from that car, he would have been found guilty. 100% positive."

Without that crucial evidence, the jury found Carpenter not guilty.

"They wanted the DNA, and in the end, we didn't have sufficient evidence to get a guilty verdict," said Romley.

The cloud of suspicion haunted Carpenter until his death four years later. To this day - police insist they identified the killer.

They just couldn't prove it.