A Livermore youth golf instructor charged with molesting three teenage boys planned from his jail cell to kill his alleged victims, authorities said Tuesday.

But the plot failed when investigators were tipped by an informant that Andrew Nisbet, 32, was arranging to have his former students killed, according to a complaint filed in Alameda County Superior Court.

The new frightening allegations have resulted in more charges against Nisbet, including three counts of solicitation of murder. Nisbet, arrested in December 2013, has already been charged with 75 counts of molestation and lewd acts with minors.

On Tuesday, prosecutors revealed that Nisbet, who is being held without bail at Santa Rita County Jail, met with someone he thought was a hitman in March, giving him names, locations, vehicle information and other relevant details of his alleged victims, saying that he wanted them "taken care of."

Initially, Nisbet began exchanging letters with someone he thought he could hire to kill his alleged victims, all of them teenage boys, according to a declaration of probable cause. After the informant tipped off investigators, a county investigator posed as another hitman and visited Nisbet in jail.

The undercover investigator, wearing recording devices, told Nisbet he was a "mechanic and could fix a car for him," according to the probable cause statement, and made a pistol-shooting motion with his hand.

During his meeting with the undercover officer posing as a hit man, Nisbet mouthed the victims' names and promised to pay upfront to show he was serious, according to the complaint. He also suggested that the investigator take the victims' cellphones, so that their murders would appear like a robbery.

Investigators reportedly found numerous letters in Nisbet's jail cell discussing the murder-for-hire plot as well as one that had driving directions to a victim's house in Pleasanton. A spokeswoman for the Alameda County District Attorney's Office declined to elaborate on the allegations.

Nisbet is a nationally recognized junior golf instructor, recognized by the U.S Kids Golf Foundation as a "Top 50 Master Teacher." He also directed the U.S. Kids Golf Bay Area Tour, a series of one-day tournaments for children ages 5 to 14. He was set to receive the North California Section of the PGA 2013 Junior Golf Leader Award when he was arrested Dec. 7.

Nisbet is due back in court June 10.

Contact Karina Ioffee at kioffee@bayareanewsgroup.com. Follow her at Twitter.com/kioffee.