SAYREVILLE, N.J. — The freshmen were easy prey in the locker room. They slinked away when the older varsity boys barreled in, blasting their music, shooting each other with Nerf guns and stripping down with the kind of confidence that freshmen could only fake. Intimidated by the older boys, most played invisible. But on the day of the second game of the season, Sept. 19, the freshmen became targets in a pastime very different from football.

“Hootie hoo,” the older players yelled before their home game that night, flicking the lights on and off and on again. Then they tripped a freshman in a T-shirt and football pants, letting loud music muffle any noise the boy made as he fell. Two pinned the younger boy’s arms, while others punched and kicked him — not viciously, but hard enough to matter, two witnesses said. He curled into the fetal position and was groped by his attackers.

What happened during that episode and in three other locker room attacks in subsequent days at Sayreville War Memorial High School prompted the arrest of seven varsity players on hazing and sexual abuse allegations, the cancellation of the football season and another round of introspection about the sport and its recent spate of scandals.

Prosecutors accused three of the players of more serious crimes, including an act of sexual penetration on one victim. But the investigation may be complicated by conflicting accounts of what occurred, according to interviews by The New York Times with two victims and multiple witnesses to three attacks. The task of prosecutors has also been made knottier by the atmosphere of recrimination that has seized the school since the season’s cancellation, with text messages flying back and forth and students dropping names with devastating casualness on social media. The search is on for the snitches — the kids who killed football in Sayreville.