(CNN) A father dedicated to helping prevent mass shootings after his daughter was killed in the Sandy Hook massacre has died of an apparent suicide.

The body of Jeremy Richman, 49, was found in his Connecticut office building Monday morning, Newtown police said.

The neuroscientist was the father of 6-year-old Avielle Richman, who was among 20 children and six adults killed in the 2012 Sandy Hook Elementary School shooting

Avielle Richman, 6, was killed in the Sandy Hook shooting.

His death is the third suicide in the past week related to school massacres.

Police said they "will not disclose the method or any other details" of Richman's death, other than it does not appear to be suspicious.