AUBURN – A Superior Court justice will decide Monday whether a local man accused of stealing an airplane and crashing it outside Montreal should be committed to a mental health institution instead of having to stand trial.

Jason Begin faces a charge of theft, along with four previous sex charges.

Police say the 26-year-old Lewiston man was trying to avoid prosecution for the charges of gross sexual assault and unlawful sexual contact when he stole a Cessna 150 from Twitchell’s Airport in Turner on Sept. 27, 2003.

Begin, who does not have a pilot’s license, was headed for Montreal when he ran out of gas and crashed the two-seater plane in an open field.

Ten months after the accident, the state and Begin’s lawyer agree that he should not be held responsible for stealing the plane because he was too mentally ill at the time of the incident to understand that he was doing something wrong.

On Monday, Begin is scheduled to appear in Androscoggin County Superior Court to enter a plea of not criminally responsible, formerly called not guilty by reason of insanity, for the theft charge.

The decision to accept his plea lies with Superior Court Justice Thomas E. Delahanty II.

Before making his decision, Delahanty will hear testimony from Dr. Ann LeBlanc, the director of the Maine State Forensic Service. LeBlanc evaluated Begin to determine his state of mind at the time of the plane crash.

Begin, who lived on Howe Street, survived the crash with minor injuries. The plane, which belonged to an airplane mechanic from Buckfield, was destroyed.

According to court papers, Begin was taken to a mental institution in Montreal after the accident. A psychologist there determined that he could not be held responsible for any violations of Canadian law.

Begin’s local lawyer, Verne E. Paradie Jr., asked the state to consider making the same determination for his charges in Maine.

Assistant District Attorney Deborah Potter Cashman said she was hesitant at first to accept Begin’s claims that he could not be held criminally responsible, but she changed her mind after talking with LeBlanc.

“He has some serious mental issues,” Cashman said.

Begin’s mother told police after the plane crash that her son suffered from depression, and it became worse after he was charged with the sex crimes.

The three charges of unlawful sexual contact and one charge of gross sexual assault facing Begin stem from two incidents in 1998 and 2001. They involve a girl and a boy, who are both younger than 14.

Begin was scheduled to go to trial for the sex charges last November. He told his mother at one point that he was scared to go to jail because he was afraid that the other inmates would beat him up, according to a police affidavit.

If Delahanty rules that Begin cannot be held criminally responsible for stealing the airplane, he will be handed over to the state Department of Behavioral and Developmental Services. He likely would be committed to the state’s psychiatric hospital for an indefinite period of time.

Cashman said she will likely dismiss the sex charges if Begin is sent to the former Augusta Mental Health Institute, now called Riverview Psychiatric Center.

Since it likely would be years before Begin could leave the hospital, even with a day pass, he would not be a threat to his victims or other children, Cashman said. And, she added, dropping the charges would avoid having to put Begin’s young victims on the stand.