After more than two and a half years lying in a shallow grave in a “vast” and “rugged” part of California’s Angeles National Forest, the remains of long-missing 20th Century Fox executive Gavin Smith were identified by his dental records, police said.

Smith’s disappearance has remained an unsolved mystery since he was seen pulling away from his friend’s house in Oak Park, Calif., in a black Mercedes-Benz around 9 p.m. on May 1, 2012.

He was never seen alive again and now law enforcement officials say they believe he was murdered in his car. The remains uncovered last week had indications of “trauma,” they added.

“There are indications that there was some trauma,” said Los Angeles County Sheriff’s Department Lt. Dan Dolson in a news conference on Thursday. “There was evidence in the car that indicated that he was killed in the car.”

Dolson added that while police have not ruled out that he suffered from gunshot wounds, they “don’t believe that was in play.”

The Los Angeles coroner is conducting an autopsy that police hope will reveal the cause of death.

But an official with that office told the Los Angeles Times on Thursday that after years of decomposition in the elements, it may never be known how Smith died.

“It could be months, if ever, worst-case scenario,” coroner’s Lt. David Smith said, according to the Times.

The discovery of a body in this drawn-out case is a “crucial piece of evidence” that could finally lead to an arrest and conviction of the person or persons responsible, Dolson said.

While the sheriff’s department is being tight-lipped about the evidence it has already uncovered, Dolson revealed that investigators believe they know the “how and why” of Smith’s murder.

The human remains were found by hikers on Sept. 26 in a shallow grave in a remote part of the forest near Palmdale. According to NBC4, hikers also found clothing in the area.

“There was a dog with the hikers that alerted the hikers to something in that area,” said Dolson, who added that the department had indications that Smith could have been buried somewhere in that area. He would not specify what information caused investigators to believe that he might be there, or to what extent a search had been conducted.

For a year after he vanished, police found no trace of the executive, who was a liaison between theaters in Dallas and Oklahoma City and the Hollywood movie studio. And Smith, an actor, father of three and 6-foot 6-inch former college basketball player for John Wooden’s UCLA teams,   would have been hard to miss.

“He had a million-dollar smile,” his only sister, Tara Addeo, told NBC4.

His wife, Lisa Smith, said early on that she believed he was murdered. In an interview, she acknowledged that they had struggled with infidelity, drug addiction, and money woes.

“Do I feel betrayed? Of course, I loved him dearly,” Smith told “Inside Edition” in 2012.

Months later, in March 2013, police had a major break: Smith’s luxury car was found in a storage facility that belonged to a known drug dealer named John Creech.

At that point, police were convinced that Smith’s disappearance was a homicide. Detectives called Smith’s sister, Addeo, in Nevada to break the news, according to NBC4.

“He said I don’t know how to tell you this but Gavin isn’t coming back,” Addeo recalled. “There was enough biological evidence to prove that Gavin was killed.”

Creech, who is currently serving an eight-year prison sentence for an unrelated charge, remains a person of interest in the case. When Smith’s car was found, police executed a search warrant at Creech’s home but found nothing that would lead to Smith’s body — or to his killer.

Smith was allegedly having an affair with Creech’s wife, Chandrika Creech, whom he had met while in rehabilitation. But Creech’s defense attorney told the Hollywood Reporter in 2012 that they had never met.

“His status remains the same to us at this time,” Dolson said of Creech. “There’s still a lot of additional evidence to analyze before we move forward.”

“The investigation is ongoing at this point we are not charging anybody with anything. We’re optimistic that sometime in the future that we will be able to.”

Smith was declared legally dead on May 1, 2014 — two years to the day after his disappearance. The date of death was listed as May 1, 2012.