As the nation grieves for the 20 children and six adults killed in Friday’s mass shooting at Sandy Hook Elementary School, more details are being released about suspected gunman Adam Lanza, including that he attended a Connecticut college when he was 16.

Lanza, 20, enrolled at classes at Western Connecticut State University in the summer of 2008, when he was a teenager, the Hartford Courant reported. Lanza had been homeschooled for a portion of his high school years.

The gunman had a 3.26 grade point average at Western Connecticut State, including an A in a computer class, an A-minus in American history and a B in macroeconomics, the school’s spokesman, Paul Steinmetz, told the newspaper.

Lanza also dropped out of a German class and received a C in philosophy, according to Steinmetz.

Students in Lanza’s college classes remembered him as a shy young man, the same description given by those who knew him in high school.

While Lanza’s high school peers said he demonstrated social awkwardness and was clearly uncomfortable in social situations, the college students chalked up his demeanor to being younger than other Western Connecticut State students.

"We attributed him being quiet to him being so much younger than the rest of us," classmate Dot Stasny, 30, told the Associated Press. "I assumed he was this super smart kid who was just doing extra course work."

Another classmate, Gretched Olson, also said she believed Lanza was quiet because of his age.

"We never really knew much about him," Olsen, who was in Lanza’s German class, told the AP. "We said 'hi' to him from time to time. He smiled sometimes."

Students at Newtown High School, which Lanza attended, described him as shy and withdrawn. They also noted that he would bring a briefcase with him to school while other children carried backpacks.

"He would always have his head down walking to class with his briefcase — kind of scurrying," recalled Newtown High School classmate, Tracey Dunn, according to USA Today. "He never sat down or said anything to kids at his locker. He was just there in the background."

Lanza is suspected of first killing his mother, Nancy Lanza, at their Newtown home on Friday morning, and then going to Sandy Hook Elementary School and killing 20 children and six adults with a Bushmaster .223-caliber rifle.