EL RENO, Okla. (AP) — An Oklahoma man is facing a first-degree murder charge after allegedly leaving his 3-year-old son inside a hot truck.

The state medical examiner's office on Friday identified the boy as Ryker Daniel Kolar. The cause of death is pending.

Police say 33-year-old Adam Kolar appeared to be intoxicated at the time of his arrest on Thursday in El Reno, located west of Oklahoma City.

First responders were not able to revive the boy after he was found in a car seat in the truck, which had its windows rolled up.

Adam Kolar remained jailed on Saturday.

Jail records did not list an attorney for Kolar.