ATHERTON, Calif. (KRON) — A mystery has been unearthed at a mega mansion in Atherton after a landscaping crew found a Mercedes-Benz sportscar buried under one of the pristine property’s gardens. On Friday, new clues surfaced on the mansion’s former owner who was once convicted of murder.

The wealthy family who lives at 351 Stockbridge Avenue has already been exonerated because police determined that the vehicle was hidden underground before they moved in.

The Atherton Police Department stated, “The vehicle was possibly buried sometime in the 1990’s and was buried approximately 4-5 feet into the ground. Cadaver dogs made a slight notification of possible human remains.”

351 Stockbridge Avenue was bought in 1994 by the family trust of John Bocktune Lew, property records show. The 1994 sellers were also trustees of John Bocktune Lew family.

The mansion was built in 1990, has five bedrooms and seven bathrooms, and was most recently sold for $15 million in March of 2020, according to Zillow. The mansion itself is 12,634-square-feet, and it sits on 1.63 acres of gated property.

Today the property is worth more than $18 million, according to Zillow. But the pricey property is now a crime scene for a case police are calling a “suspicious circumstance” investigation.

San Mateo County District Attorney Stephen Wagstaffe told KRON4 that the vehicle was a sportscar convertible. “It’s down there pretty deep. Our crime lab is carefully using hand shovels. So far, there is no evidence of human remains,” he said.

The Atherton Police Department also confirmed that no definitive evidence of human remains had been found as of Friday afternoon.

“The vehicle is a Mercedes-Benz and was reported as stolen to the Palo Alto Police Department in September of 1992.  The possible owner of the vehicle is believed to be deceased.  We are waiting for DMV records,” Antioch police stated.

Lew died seven years ago at age 77, according to death records.

A cadaver dog was brought back to the excavation site on Friday. “The cadaver dog again made a slight notification of possible human remains,” police stated.

John Bocktune Lew’s criminal history

The Atherton mansion mystery deepened when court documents, and a 1999 KRON4 news report, revealed Lew’s criminal history. His criminal history includes a murder conviction and yacht insurance scandal.

In 1966, Lew was convicted in Los Angeles County of murdering his secret lover, Karen Gervasi, court documents show. His conviction was later reversed by the California Supreme Court and he was released from prison. Court documents from his appeal state, “Defendant, though married, had for some time been enamored of Karen; they were sexually intimate, and there was some contemplation of marriage. On the day Karen died defendant had picked her up at her parents’ house. Karen expressed a desire to fire defendant’s pistol. He agreed to take her to a pistol range, and they stopped at his apartment to get the gun.”

The appeal states that Karen’s death was an accidental shooting. “The clip fell to the floor, and as he bent over to pick it up he heard a shot. The bullet struck Karen in the left temple just above her eye. Defendant became hysterical when he discovered that Karen was no longer breathing. Karen was lying on her back and bleeding profusely around the head.”

Lew served three years in prison before his conviction was overturned and he was released from custody.

The sportscar was found underground at 8:50 a.m. Thursday. The property was surrounded by Atherton police detectives and a San Mateo County Sheriff’s Crime Lab while Bay Area television news helicopters flew overhead.

Investigators paused their excavation at 10 p.m. Thursday and resumed digging at dawn Friday. They found unused bags of concrete throughout the vehicle.

atherton mystery
Atherton mystery mansion (Photo by Sara Stinson / KRON4)

“The majority of the top of the vehicle has been uncovered, but the entire interior of the vehicle is also filled with dirt,” Atherton police Cmdr. Dan Larsen said. “They have to go through it slowly and methodically as they continue the excavation.”

“Due to the unknown nature of why the vehicle was buried, cadaver dogs were called to the scene,” APD wrote. “The motive and circumstances surrounding this incident are under investigation.”

Police said they will release updated details on the Atherton mansion mystery this afternoon.

Yacht Insurance Scandal

Lew was 62 years old and living in Atherton when he attempted to hire someone to sink his luxury yacht in 1999, according to police. Lew allegedly paid undercover officers $30,000 in cash to intentionally sink his yacht near the Golden Gate Bridge.

Lew didn’t realize he was talking to undercover officers when he threatened that if anyone revealed the secret, “his people” would kill them, according to police. Lew’s plan was to claim that the boat was stolen and collect $1.2 million from his insurance company, KRON4 reported in a 1999 news story.

While Lew was in China on a business trip, officers took the boat from the marina and transported it to Stockton to store as evidence. When he returned from China, Lew reported his yacht as stolen to the Redwood City Police Department. He was arrested on suspicion of insurance fraud shortly after.