RIDGEFIELD, Conn. — The father of a 15-month-old boy who died after being left in a car in July turned himself in on Tuesday after being charged with negligent homicide.

The man, Kyle Seitz, 36, was arrested by the Ridgefield police and released on a promise to appear in Danbury Superior Court on Wednesday. He is charged with a misdemeanor punishable by up to a year in prison.

Mr. Seitz was supposed to take his son, Benjamin Seitz, to day care on July 7 but instead went to work, the police said. Benjamin was left in the car for more than seven hours as temperatures climbed into the upper 80s, investigators said. Mr. Seitz found Benjamin in the car when he went to pick him up from day care, and he took the boy to a hospital.

The medical examiner ruled the case a homicide.

A phone message seeking a comment from Mr. Seitz was not immediately returned on Tuesday.