Nope. According to the Barre City School Policies, 2.0 Use of the school building may NOT include....:
2.6 Functions (Are) determined by the building administrator to be an inappropriate use of school facilities.
Mott's activities obviously fall under that category.
Interestingly, also prohibited is: 2.4 Groups (Are) intended to overthrow the government, by force, violence, or other unlawful means.
Given whom he's got pictures of, Mr. Treece may be edging close to that line.