The convicted teenage gunman Max Wade was transferred to San Quentin State Prison on Thursday as new court documents and interviews shed more light on his activities and childhood.

In addition, a Marin County sheriff’s detective confirmed that Wade was one of several people to be investigated as a potential suspect in the murder of a 75-year-old Tiburon woman in 2009. Neither Wade nor anyone else has been charged, and the case remains open.

Wade, who was sentenced last week for a gun ambush in Mill Valley and the theft of a $200,000 sports car in San Francisco, was moved from Marin County Jail to San Quentin on Thursday morning to begin his prison life.

Wade, 19, will spend about 90 days at San Quentin while prison authorities decide where he will serve the bulk of his sentence, said prison Lt. Sam Robinson.

Wade is being held in the highest security unit at the prison because of the notoriety of his case and a previous attempt by Wade’s allies to break him out of juvenile hall, Robinson said.

Wade will have to serve about 16 years in prison before beginning a life sentence, at which point he can start applying for parole.

Wade’s trial lawyer, Charles Dresow, said he is preparing an appeal.

Wade was convicted in October when a Marin County jury found him guilty of trying to murder Landon Wahlstrom, 18, in 2012. Wade, then 17 years old, rode a motorcycle up to Wahlstrom’s truck in Mill Valley and repeatedly fired a gun into the cab.

Wahlstrom’s girlfriend, 17-year-old Eva Dedier of Terra Linda, was also sitting in the truck, but the jury found insufficient evidence to prove Wade was trying to kill her as well.

The prosecution alleged that Wade launched the attack because he desired Dedier for himself and was jealous that Wahlstrom was dating her.

The jury also convicted Wade of stealing a $200,000 Lamborghini Gallardo Spyder from a San Francisco dealership in 2011. But they found insufficient evidence to prove that Wade was actually the burglar who broke into the dealership through an upper window and rappelled down to the car.

Marin County sheriff’s detectives found the Lamborghini and evidence linking Wade to both sets of crimes after tailing him to a storage locker in Richmond. Wade was arrested after trying to run from detectives and pulling a Glock handgun from his waistband.

Wade, who was charged as an adult, pleaded not guilty to the crimes and did not cooperate with authorities before the trial. However, a court probation report released this week shows that Wade made numerous admissions in a recent interview with Deputy Probation Officer My Tran.

According to Tran’s synopsis of the interview, Wade admitted to shooting at Wahlstrom’s truck, but said he did not think the passenger was Eva Dedier. He said he thought the passenger was Wahlstrom’s brother and initially changed his mind about shooting, but then fired five shots anyway.

“He did not intend to kill the victim,” Tran wrote, summarizing Wade’s comments. “He stated that he has been involved with shooting guns since age six or seven. He would not have missed the victim if he did not change his mind.”

Wade said “he feels sorry for what he did to Eva and never would want to harm her,” Tran said. “He is sorry for doing this and for the disturbance that he caused in the neighborhood of the shooting.”

The report also details the evidence found in the Richmond storage locker, including police uniforms, latex gloves, radio signal jammers, guns, ammunition, rapelling equipment, fake identification and plans to stage a jewelry store heist in San Francisco and escape by helicopter.

In addition, investigators found a sales contract indicating that Wade planned to sell the Lamborghini, which belonged to television chef Guy Fieri, for $201,500 by shipping it from the Port of Oakland to a dealership in the Dominican Republic.

The shipping contract carried the signature of Wade’s alias, “Carmine Leone Colombo,” an apparent reference to the New York mob family.

The probation report also includes a detailed description of Wade’s juvenile criminal history, which dates to September 2007, when Wade was 13. The record includes seven reports from the Tiburon Police Department and one from the former Twin Cities Police Department.

The allegations included setting off a “stink/smoke” bomb in a clothing store; spraying another child in the face with an unknown substance; posting images on his MySpace account of a BB gun, brass knuckles, a marijuana leaf and a Ku Klux Klan emblem; punching a girl classmate between her shoulder blades; stealing girls’ journals and threatening to post them on the Internet; assaulting his mother; stealing his mother’s truck; and hosting a large teen party at a Tiburon home while the actual residents were away on vacation.

Wade, who went to Del Mar Middle School in Tiburon and then attended Redwood High School, received a series of informal probations, diversions or citations.

The case has left lingering questions about how Wade was able to acquire the vast collection of weapons and crime paraphernalia found in the Richmond locker.

Sheriff’s Deputy Greg Garrett, who was the lead investigator on the case, said Wade apparently financed his operations by selling marijuana and fake identifications to Marin County teens. Garrett said Wade generated “significant” revenue from the IDs, selling hundreds of them at $100 a pop.

The Glock handgun Wade tried to pull on detectives during his arrest had been purchased from another young associate for $500 worth of pot, authorities said. The associate, Carlos Ayala, was later convicted of selling it.

As for the gun used in the Mill Valley shooting, investigators traced it to a man who said he lost it some time ago during a move in the Sacramento area. It was unclear how it ended up in Wade’s hands, Garrett said.

Garrett also confirmed that investigators looked hard for links between Wade and the murder of Joan Rosenthal, the 75-year-old Tiburon woman shot to death outside her home in 2009. Investigators said Rosenthal was apparently pushed to the ground and shot at close range, and there was no evidence of a burglary.

Wade, who performed hundreds of Internet searches about the crimes for which he was convicted, also ran 54 searches on the Rosenthal slaying, Garrett said. Also, he was known to joke about the murder and the police.

But Wade was one of many possible angles that investigators explored, and sheriff’s investigators neither sought charges against him nor ruled him out. The case is still open pending other developments.

Contact Gary Klien via email at gklien@marinij.com or https://twitter.com/GaryKlien