Groton- The Mystic Fire Department probationary volunteer officer already facing a first-degree arson charge for allegedly setting fire to a house at 23 Library Street in July now faces two more arson charges for smaller fires in August.

Groton Town police Wednesday charged 21-year-old William Celtruda with two additional counts of first-degree arson for fires they considered suspicious on Aug. 12 - one on Little Gull Lane at 3 a.m. and another on West Mystic Avenue almost two hours later.

Though the historic Library Street house was destroyed, the August fires were quickly extinguished by Noank and Mystic fire departments and caused little damage.

Celtruda was also charged with third-degree burglary for breaking into the garage of the Noank house, where the fire started, police said. It spread to the attached breezeway.

It appears Celtruda was charged with first-degree arson because the buildings were occupied, and he had reason to believe they were occupied.

Other factors that would lead to a first-degree charge do not apply: there were no injuries, the fire was not caused to collect insurance, and no responding firefighters were subjected to a substantial risk of bodily injury.

Police said they could not comment further, and the warrants in both cases have been sealed.

Celtruda is currently being held by the Department of Correction. He was presented at New London Superior Court Wednesday and held on an additional $250,000 bond.

Celtruda, who lives at 286 Judson Ave. with his grandparents, worked for the Mystic Fire Department for about six months and is part of a family with longtime connections to the department.

Celtruda also has a pending case from May in which he was arrested by Waterford police for second-degree threatening and second-degree harassment. His next court date is Sept. 8.

K.WARCHUT@THEDAY.COM