A homeless man was arrested Thursday after attacking a 7-year-old boy in Queens, according to the New York Police Department.

CBS 2 reports the young child is in critical condition after the attack and the suspect – identified as Laurance Gendreau – is currently undergoing psychiatric evaluation at Jamaica Hospital. The suspect, described as “emotionally disturbed,” faces charges of assault and harassment.

“I went after him, followed him, called 911, and the police found him,” Naftali Portnoy, the boy’s grandfather, said in an interview with CBS2. “His first words out of his mouth, ‘I’m bipolar,’ and something about ‘kill the kid, wanted to kill, I could have killed.’”

Portnoy recounted how the child and his brother were waiting for a pizza delivery in their driveway at around 5:00 p.m. local time in Kew Gardens when the attack occurred. Portnoy said the suspect, who was shirtless, picked up the boy and slammed him on the ground, prompting his brother to run inside the house to call for help.

“You heard that scream, you knew something serious was going on,” Portnoy recalled. “It’s a kid that was picked up and smashed to the ground.”

“The child is intubated and the child is sedated. We hope and we pray that God’s watching over him and he’ll be OK and that nothing like this happens to anyone,” he added.

Rabbi Gary Moskowitz, a resident of the neighborhood, told CBS 2 that the alleged attack sent shockwaves through the community.

“As a parent, I’m horrified. I have three small children here and I’m always concerned about safety,” he said.