Christian Karl Gerhartsreiter, the German man who convinced New England high society he was a scion of the powerful Rockefeller family, was found guilty Wednesday of murdering a California man.

A Los Angeles jury deliberated for one day before rendering its verdict against Gerhartsreiter, a 52-year-old German who posed as Clark Rockefeller to insinuate himself into elite social circles. They did not buy Gerhartsreiter’s attorney’s claim that he suffered from delusions and was legally insane.

Gerharttsreiter, who emigrated to the U.S. from Germany in 1978 at 17 years old, was living in San Marino, Calif., in 1985, when his neighbor, John Sohus, 27, disappeared.

Sohus’ skeletal remains were found nine years later in the backyard of his former home when excavators were digging a swimming pool for the new owners. His wife, Linda Sohus, also disappeared, but her body has never been found.

Gerhartsreiter was a person of interest in the murder, but eluded authorities in part by using a number of aliases, including Clark Rockefeller.

He was finally caught in 2008 after he abducted his 7-year-old daughter from Boston and took her to Baltimore, where he was arrested and ultimately convicted of kidnapping charges.

Since coming to the U.S., Gerhartsreiter told a number of tall tales, including claims of being a surgeon, ship captain and a member of the Rockefeller family. He used his charm to get a woman to marry him so he could get his green card. The German native’s Harvard-educated wife knew him as Clark Rockefeller.

Sohus was the son of Gerhartsreiter’s landlady in San Marino, and Sohus’ step-sister Ellen Sohus said she believed her brother thought the renter was a threat to his mother.

“There may have been something that he felt he needed to protect his mom,’’ she told the Los Angeles Times.

She said her brother “was loved” and spoke about him as if he was still living.

“I love my brother,” Ellen Sohus told the Times. “My father adored John and was heartbroken when he found out he was murdered. He had family.”

Habib Balian, the prosecutor overseeing the case against Gerhartsreiter, said the imposter’s past had him concerned that he might fool the jury.

“We’re very, very relieved. Sometimes, you’re afraid that this guy’s conned so many people for so many years that this would be the one last time he pulled off his last con,” he said. “But that didn’t happen. The system worked. The jury looked at what was reasonable, rejected what was unreasonable, and they came to a just verdict.’’

Gerhartsreiter faces up to 26 years in prison following the guilty verdict. Fox News reported that his sentencing is scheduled for Friday.