Crane’s promiscuous lifestyle meant that many people had a motive to murder him. 

Outside Crane’s apartment, crime scene

There was no sign of forced entry.  Crane was a light sleeper and would have jumped up at the sound of an intruder.  Detectives thought it likely Crane had let the murderer into his home.

Investigators wondered if a woman could have killed him.  A woman could have been mad at him because he discontinued a relationship or because she belatedly discovered that he had videotaped their sexual relations.  Indeed, many of the women he slept with were upset when they were told after his death that they were on his home movies.

A spouse is always a potential suspect.  Patti Crane was jealous, estranged from her husband and, at the time of his death, seeking a divorce.  There were reports of fits of rage, like the time she had supposedly thrown a VCR at Bob Crane.  However, she had a solid alibi in Washington state for the time of the slaying.

Wound to Bob Crane’s head, autopsy photo

The physical evidence in the apartment suggested a male attacker.  Medical examiner Heinz Karnitschnig, usually called “Dr. K,” believed the murderer was male because “The killer’s first blow laid open Crane’s scalp, covering the weapon with blood.  The second blow was delivered with a short arc, slinging only a couple of droplets onto the ceiling and table near the bed.”  As Graysmith wrote, “Dr. K felt that if the attacker had been female, she would have had to swing the heavy weapon in a wider arc, which would have flung a trail of blood onto the ceiling.”  The depth of the wounds suggested a “very strong man.”

Of course, even if a man had dealt the blows, it would not rule out the possibility that a woman was behind it.  She could have recruited a male to do the job.  Investigators pursued numerous leads.  They could find nothing connecting Patti Crane to her husband’s killing.  Many women, together with their husbands and boyfriends, were also checked out.

A large black bag was found on the bed with the murdered man.  It had two zippers, one at the top, another on the side, and both were undone.  It was empty except for a few pieces of paper and some old tickets.  Detectives surmised that the killer had probably taken whatever had been inside it.  They were not able to find anyone who could say with certainty what that was.

A countertop had a half-empty bottle of Scotch and a bottle of gin.  Victoria Berry told police that Crane never touched Scotch.

Crane’s corpse on a gurney

The cord around the neck seemed a tantalizing clue.  Was a woman who had been filmed having sex with Crane – perhaps without her knowledge at the time – trying to make a statement?  Or a disgruntled husband or boyfriend who discovered a tape of his woman making love with the actor?  The killer had walked past electrical cords of various types to fetch the VCR cord, suggesting the choice was deliberate.  Some thought tying around the victim’s neck pointed to a female murderer.  Having less physical strength on average than her male counterpart, a murderess might not be certain her blows had killed and want to make doubly sure with strangulation. 

Others thought the cord pointed straight to John Carpenter.  Their friendship had been founded on making videos.  Tying the cord around Crane, then cutting it symbolized the ending of that friendship.

Some witnesses said the relationship between the electronics expert and the late actor had been growing tense.  Others speculated that Carpenter might have wanted a closer relationship than Crane would allow.  Several people acquainted with Carpenter said he was bisexual and believed he had a crush on his best friend.  The heterosexual Crane might have rebuffed Carpenter’s advances and sent him into a rage.  It was also considered possible that Crane simply wanted out of the friendship and Carpenter killed out of fury at that rejection.

Investigators were very interested in tracking John Carpenter’s movements immediately before and after the Crane slaying.  Very early in the morning of June 29, Carpenter phoned Cathy Nugent, day manager at the Sunburst Motel where he was staying.  It was the day he was to leave Arizona for California.  “I thought I had a reservation originally for the limo at 10,” he told her in an urgent voice, “then I realized I don’t have an 11 a.m. flight, that’s my arrival time in California.  That I had a 10 o’clock flight.  So I called up again.  Is there any way I can get my limo at 9?”

“No,” Nugent replied, “there’s no way.  Nobody at the limo service to take your order now.  You’ll have to go by cab.  We better call that cab now, Mr. Carpenter, because sometimes it takes a long time for it to get here.”

The cab picked him up at about 8:40 a.m. and got him to the airport about 9:15 a.m.  He rushed to the Continental Airlines desk where they told him that his flight left at 11 a.m.

It arrived in Los Angeles at 11:36 a.m.  He went home and found his car having trouble so he took it to an auto repair shop.  Then he went to his job.

At 2:30 p.m., Carpenter phoned a woman at the Windmill Theatre in Scottsdale.  She told him she had heard there was “some problem at Bob Crane’s apartment, that the police were investigating the incident.”  A few minutes later, Carpenter called another worker at the theater and asked if Bob was there.  The woman said he was not.  “Just leave a message for him,” Carpenter said.  “Tell him I arrived in town OK.”

Carpenter placed a call to Bob Jr. at about 3 p.m.  They spoke for a couple of minutes and Bob Jr. did not recall anything important being said.

Approximately 10 minutes later, Carpenter rang Crane’s apartment.  Victoria Berry answered the phone and handed it to  a police lieutenant, Ron Dean.  He told Carpenter that he was investigating an incident.

“I’m John Carpenter,” the caller told him.  “I was with Bob Crane last night.  I called him at one this morning to tell him I was preparing to return to California.  He told me he was going to be sleeping late in the morning.”

Carpenter did not ask Dean what it was that the police were investigating.

He called back in a half hour.  Dean asked him some questions and requested Carpenter’s phone number.

Again Carpenter expressed no curiosity as to why police were in his best friend’s home.

Police examined the Cordoba Carpenter had rented.  Inside that vehicle, on the passenger door, they found tiny spots and a thin line of what appeared to be dried blood.  The areas were tested.  They were blood – type B human blood, the same blood type as Bob Crane and about 10% of the population.  At the time, no DNA test was available that could definitively say whose blood it was.

Carpenter was questioned.  He adamantly denied having anything to do with the actor’s killing and said he did not know how blood could have gotten inside the car.

Police wanted to charge Carpenter but did not.  A few blood spots that could be the victim’s or could be someone else’s, reports of tension in their friendship, Carpenter’s desire to leave Scottsdale in a hurry, and his lack of curiosity about police presence in Crane’s household – all of these things were suspicious.  But they did not add up to enough evidence to sustain a murder charge.

In 1985, a British molecular biologist developed the DNA profiling that could match a genetic material with an individual.  In 1989, investigators tried to match the blood in Carpenter’s rented car with Bob Crane.  The test results came back inconclusive.