John Mann IV pleads guilty in Henry Hernandez’s death

John Mann IV killed Henry Hernandez, 16, in 2019, prosecutors said. (Mugshot: Suffolk County District Attorney’s Office)

A New York state young man has pleaded guilty to killing a 16-year-old over a stolen truck, prosecutors said.

John Mann IV, 20, entered his guilty plea last Friday for manslaughter in the first degree in Henry Hernandez’s death, according to the Suffolk County District Attorney’s Office. He had first been indicted for murder in June 2022.

“The violent end of this young victim’s life and the way his body was disposed of shows the cold-hearted and brutal nature of the defendant,” Local DA Raymond A. Tierney said. “What makes this murder even more sad is that the victim Henry was only 16 years old and had his whole life ahead of him.”

Authorities said that Mann and Hernandez, who was homeless, knew each other and had become acquaintances in March 2019. Soon after, Hernandez went to the defendant’s home on Jay Road in the hamlet of Centereach and stole a truck belonging to Mann’s father, prosecutors wrote.

According to authorities, Mann lured the teenager to a location known as the “Sand pit” on June 2, 2019. He duct-taped the boy and hit him multiple times with a blunt object. Then he put the body in a hole and covered it with debris, prosecutors said. He later put the remains in a plastic tub and transferred it to his next-door neighbor’s property.