Lanza's mother, Nancy Lanza, who he also killed before taking his own life, had considered suing the school because she thought school officials weren't doing enough to stop the taunts and attacks, the New York Daily News reported Sunday.
She even accompanied her son to school in an attempt to catch Lanza' fellow students attacking him, the unnamed family member said.
The relative said Nancy Lanza would ask what had happened when Adam would come with bruises and "he wouldn't say anything. He would just sit there."
After the sixth grade, Nancy Lanza switched him to another school.
Adam Lanza ultimately went on his deadly rampage rampage at Sandy Hook Elementary School in Newtown, Conn., on Dec. 14 using guns bought by his mother, who was known to take him out target shooting. He was 20.