The body of Palo Alto woman Wamaitha Kaboga-Miller was found in her car in Newark on Sunday, more than five weeks since she went missing, police said Monday.

The discovery was a tragic conclusion to a baffling disappearance that had confounded her family, law enforcement and friends and led to multiple searches of the region by volunteers.

Kaboga-Miller, 66, was reported missing after leaving her Crescent Park home on Aug. 17. California Highway Patrol officers found her body in a vehicle off of state Highway 84 east of Thornton Avenue in Newark, where they were responding to a separate crash involving an overturned car shortly after 3 p.m. Sunday.

Her silver 2002 Mercedes-Benz CLK 430 was found under heavy brush and tree branches about 25 feet away from the unrelated car crash, according to police. An officer ran a check of the license plate number, which matched Kaboga-Miller's.

Emergency crews found a woman, later identified by the Alameda County Coroner's Bureau as Kaboga-Miller, sitting in the driver's seat, police said. They determined she had been in the car for "an extended period of time" and pronounced her dead at the scene. On Wednesday, the coroner's office said the cause of death was still under investigation.

The 66-year-old was considered at-risk because she recently had back surgery, couldn't walk far without a walker and was without oxycodone needed to suppress the pain from the procedure.

She was last seen at Country Time Market in East Palo Alto, the morning of Aug. 17. Aziz Khalil, co-owner of the market, told the Weekly that she seemed incapacitated and needed assistance in pulling out her wallet to pay for two packs of Marlboro Lights cigarettes.

Kaboga-Miller's family and friends held weekly search parties for her, including one in late August in East Palo Alto and another in Redwood City earlier this month.

Her family also offered a $25,000 reward for information leading to her whereabouts.

On Monday, Sophia Kaboga-Miller, her daughter-in-law, said the family wasn't ready to issue any comment. They learned about her death on Sunday.

Dawn Billman, a neighbor, said she and the family had held out hope of finding Kaboga-Miller alive. They thought she might just walk through the door one day.

Kaboga-Miller was helpful when Billman's daughter was ill. The families pulled together in crises, she said.

"They have been my neighbors since I moved here in 1990. She was just such a happy spirit, raising two wonderful young men," she said of Kaboga-Miller's two adult sons, Njoroge and Clovis. "It's a loss for the community. Wow. I'm just shocked."

CHP investigators are looking into the circumstances surrounding when and how Kaboga-Miller's vehicle ended up off of the freeway, according to a CHP press release.

Family and friends said they didn't understand why license plate readers on the bridge did not pick up her car.

CHP spokesman Officer Manuel Leal said on Wednesday that the bridge does not have license plate readers on the eastbound side, the direction in which Kaboga-Miller was driving. The readers are only on the westbound side at the toll booths. He was still looking into whether there are cameras of any kind on the east side, however, he said. CHP has not had any contact with the family and the investigation was handled by Palo Alto police, he said.

In an email response on Wednesday, Palo Alto police spokeswoman Janine De la Vega said that the department had followed all possible avenues.

"Our detectives checked cameras on the span of the bridge and those cameras did not have sufficient enough resolution to detect Kaboga-Miller's vehicle. This missing person case was a priority for our investigative division. We had detectives working this case for weeks, but unfortunately without credible information to point us in one particular direction or another, we were never able to find her. We feel terrible for her family and wish this would have had a positive outcome," she said.