Los Angeles police are investigating the disappearance of Darwin Vela, 22, who didn't return home from walking his dog Tuesday night. The Lab returned home alone with a bloody leash, his fiancee said.

The Los Angeles man who vanished while walking his dog Tuesday night was scheduled to testify in a third-strike burglary case against a man accused of breaking into the home of actor Nicolas Cage's ex-girlfriend, officials confirmed.

Darwin Vela, 22, was last seen about 9 p.m. Tuesday when he left his home in the 2900 block of South Redondo Boulevard to walk his dog, police said. The 90-pound chocolate Labrador retriever came back alone, Vela's fiancee told The Times, and had blood on his leash.

LAPD Deputy Chief Kirk Albanese said Friday investigators were examining the blood and "looking at all possibilities" behind Vela's disappearance, including "everything associated" with the missing man "and his movements before and his lifestyle."

Officials confirmed Vela and fiancee, Kelly McLaren, were set to testify in a preliminary hearing Thursday in a case against Ricardo Orozco, who allegedly burglarized the home of Christina Fulton, Nicolas Cage's former girlfriend, in April.

Orozco, with prior theft, robbery and sex with a minor convictions, is facing a third strike in the burglary case and if convicted could face 25 years to life in prison.

A source described Vela and McLaren as key witnesses in the case. McLaren told The Times on Thursday that she and Vela witnessed the break-in. "Without us, there isn't a case," she said.

On Thursday, a police detective testified about an encounter involving the couple, Orozco and Martin Singer, an attorney who has represented actor Charlie Sheen, according to Los Angeles County district attorney's spokeswoman Jane Robison.

The detective said that before the break-in, Orozco, Vela and McLaren met with the attorney and told him they knew of a sex tape involving Sheen, Robison said. They said they did not have the tape, the detective testified, and Singer told them he would talk only to someone who had it.

In April, computers and other items were stolen from Fulton's home, allegedly by Orozco, authorities said.

Robison noted the alleged sex tape has not materialized, and said officials question whether it ever existed. Singer could not be immediately reached for comment.

McLaren also took the stand Thursday but invoked her 5th Amendment right not to testify, Robison said. McLaren declined Friday to comment on the detective's testimony because she did not hear it.

She also declined to comment on her decision not to testify, saying she took the stand and followed the advice of her witness counselor.

McLaren said she and her family were awaiting test results that would determine if the blood on the leash was Vela's. They planned to canvass the neighborhood with fliers Friday afternoon.

Police searched the area near the couple's home on Tuesday night, McLaren said, and although a bloodhound briefly traced his scent, police found no sign of him. He left his cellphone, wallet and keys at home and has not contacted friends or family, she said.

Vela has never disappeared without notice and is "not the kind of person to do that now," McLaren said. He's especially close to his mother, who also lives in Los Angeles, she said.

"He wouldn't. Even if he could somehow leave me -- which he wouldn't, we're going to get married, we're starting a family -- he would never, ever leave his mother," McLaren said.

Police described Vela as Latino with black hair and brown eyes, about 5 feet 6 and 160 pounds. He was last seen wearing a dark green beanie, a black shirt and blue jeans.

Anyone with information about his whereabouts was asked to call detectives at (213) 996-1800 or (877) 527-3247. Anonymous tips can be submitted by calling Crime Stoppers at (800) 222-8477 or by texting 274637.

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