A $40 debt almost cost John Curtis III his life on May 5.

Curtis was driving onto Prospect Lake Drive about 7 p.m. when a 6-foot-9-inch bald man in a white Cadillac sedan shot him in the chest, a police affidavit says.

A Memorial Hospital emergency room doctor said the injury posed a “substantial risk of death.”

Police said Curtis told them he had traded methamphetamine to the suspect for two crack rocks, but then the other man began insisting Curtis owed him $40.

Harold West, 47, turned himself in Thursday morning to El Paso County sheriff’s deputies.

He is accused of first-degree assault and possession of a firearm by a felon.

The day before the shooting, a witness said, West had waved a black pistol around, saying, “I’m gonna show you what you do with a pistol.”

Then on May 5, West and Curtis argued, and West yelled: “I’m gonna murder you. Wait till you leave your mother’s house.”

Video from a nearby surveillance camera showed the suspect step out of the white Cadillac and shoot toward Curtis’s black Chrysler, police reported.

West has multiple felony convictions, including for trespassing in a vehicle with intent to commit a crime, using a weapon in a violent crime, assault, and witness and victim tampering, court records show.

He also was sentenced to two years in prison in 2005 after pleading guilty to theft.