AUGUSTA — A 15-year-old boy on Thursday admitted setting a fire that leveled the Togus Pond island home of a local couple and to burglarizing six homes, including the one that burned.

The admissions by James Croxford to those charges as well as a dozen other charges of theft and criminal mischief came at a hearing in Augusta District Court.

Justice Beth Dobson accepted the pleas and then ordered Croxford to be held at Mountain View Youth Development Center in Charleston, where he’ll probably be until he’s 21, the maximum sentence available, recommended by the prosecutor and by defense attorney Scott Gurney.

The portion of Croxford’s hearing that dealt with the more serious arson and burglary charges was open to the public. The other charges were dealt with behind closed doors.

The owners of the burned home, Alison Ames, 56, and Rob Deschamps, 57, watched the hearing Thursday, and Deschamps told the judge damages could total more than $150,000.

“At this point we are in the process of itemizing our losses,” he said. “We found it to be substantially more of a project than we ever imagined.”

The island home and contents were uninsured. The couple is living temporarily in Manchester.

“I would be comfortable with deferring” a decision about restitution, Deschamps said after the judge outlined several possibilities for her ruling. Dobson agreed to review the restitution issue in four years or sooner if needed, as well as Croxford’s ability to pay.

Assistant District Attorney David Jackson said the damages to the other properties on the island and one on the mainland amounted to about $4,000.

Croxford, a dark-haired, slim boy in a blue T-shirt and jeans, his ankles shackled, said little at the hearing except to tell the judge he understood the rights he was giving up by pleading guilty. The judge also warned him he couldn’t change his mind later.

Gurney, his attorney, said a psychological defense had been considered and that the results of psychological evaluation were “somewhat troubling,” but did not support that type of defense.

Gurney also said Croxford has spent only four months outside a secured facility since 2006, and has had eight psychiatric hospitalizations in that period. He said the teen, who has been in state custody since age 8, has become institutionalized.

“As for his future earning capacity, I think anybody out there would give it zero,” Gurney said.

He also said Mountain View officials would evaluate Croxford before releasing him, and if they found he was incapable of functioning in society, he could be involuntarily committed to a psychiatric facility.

In describing the one-day crime spree, Jackson said Croxford ran away from a secured residential property at about 3 a.m. May 4 and made his way to the Togus Pond area.

By 5:15 p.m., smoke and flames were reported rising from a camp on the island, and someone was seen paddling an aluminum boat away from the area.

Firefighters extinguished the fire using portable pumps that they ferried to the island.

Jackson said Croxford apparently stole a boat to access the island, broke into five camps there and set two small fires in one of the homes along with the fire at the Deschamps/Ames’ residence.

A homeowner’s son noticed a boat out of place on the island, and took police around to that site, where they found wearing clothing taken from one of the camps, Jackson said.

Croxford initially maintained the fire was an accident, but later accepted responsibility, Jackson told the judge.