A Juvenile Court judge Thursday found Marshall Coulter, a teenager who was shot in the head last year while trespassing on a Marigny homeowner’s property, incompetent to stand trial for a separate burglary last month.

Judge Candice Bates-Anderson issued her ruling after three forensic doctors agreed that Coulter, 15, is not competent to assist with his defense, according to a source close to Juvenile Court.

The ruling does not mean Coulter never will face possible criminal punishment. Defendants who are found incompetent are typically sent to a state hospital for treatment, with periodic re-evaluations to determine if they understand the charges against them and can assist in their own defense.

Coulter also faces an allegation that he broke into a home in the same Marigny neighborhood in 2012 and wrested a gun from a resident there.

Coulter was shot in the head last July by city employee Merritt Landry after he jumped the fence at Landry’s house in the middle of the night. Coulter underwent numerous surgeries following his shooting.

Landry was booked on a count of attempted murder, but a grand jury in March declined either to indict him or to issue a “no true bill” dropping the case.

Orleans Parish District Attorney Leon Cannizzaro announced last month that Landry would not face criminal charges. Cannizzaro said that after Coulter’s arrests on the two burglary counts, “any case that this office had against Landry was irreversibly damaged.”

From the beginning, the case has prompted protests from both supporters and critics of Landry.

According to police, Landry — an inspector with the city’s Historic District Landmarks Commission — fired on Coulter from about 30 feet away, at a time when the boy, then 14, was unarmed and “not posing an imminent threat.”

Coulter apparently had jumped the fence into Landry’s yard, prompting Landry’s backers to argue that he shot legally to protect his home and family.

Questions about Coulter’s mental state, and the possible fallout from his severe head injury, swirled following his arrest about 3:45 p.m. May 2 in the 2000 block of Royal Street, just blocks from Landry’s home. Nearby residents described him as acting oddly. One man said Coulter’s speech seemed impaired and he acted “stoned.”

Coulter also was booked in May on a warrant for an alleged aggravated battery in June 2012, police said. Residents of a home in the 900 block of Frenchmen Street “returned home and found the suspect inside of their house,” according to a police statement. “A struggle ensued, at which time the suspect armed himself with the victim’s gun. The suspect then fled the scene on foot.”

Whether Coulter could be tried as an adult on that count remains in doubt, and it is unclear whether Cannizzaro would take that option if he legally could. If he was 13 at the time of the alleged aggravated burglary, Coulter could not be tried as an adult.

Christopher Bowman, a spokesman for Cannizzaro’s office, said Thursday that he could not discuss the case.

Follow John Simerman on Twitter, @johnsimerman.