Joshua Pincoske arraignment

Joshua Pincoske appears via video for his arraignment Wednesday in Merrimack Superior Court in Concord.

A prosecutor called a 47-year-old Concord man a “serial predator” who used social media to groom young girls and had inappropriate sexual contact with at least four underage females.

Joshua Pincoske, who until recently volunteered as an assistant men’s basketball coach at Colby-Sawyer College, was arrested Tuesday and charged with three counts of aggravated felonious sexual assault and 51 counts of manufacturing child sexual abuse images.

Joshua Pincoske