Booze hound Kenny Keene was busted after cops found the boy on the backseat of his car outside a Scottsdale, AZ home.
A concerned member of the public had called them in after allegedly watching the boy sleep for 20 minutes, during which time no one came to check on the child.
When cops arrived there was no sign of Keene and the boy was sleeping on the backseat of his car.
They told KSAZ that it wasn't hot outside and that when they arrived after 9 at night the windows were cracked with enough space "sufficient for someone with an average sized arm to reach into the vehicle."
That's where the charge of endangerment of a minor comes in.
A police insider said: "Basically anyone could have got into the car, which could have been incredibly dangerous, especially with an autistic child, who would be more naive than an average child.
"Luckily nothing happened on this occasion."
When they eventually caught up with the deadbeat dad he told cops he was supporting his girlfriend, who was promoting a concert at the club, and that he'd had a couple of beers.
But he also stated he'd been checking on his son every few minutes.
Thankfully the little boy is ok, he's staying with his grandmother.
The charge of endangerment isn't a felony charge, it's a misdemeanor, but Keene could see up to six months in jail and a $2,500 fine if he's found guilty of the charge.