At age 15, Cheng Ta Saelee needed a job to support his girlfriend and their new baby, so, the police say, he established a successful marijuana trade with neighbor kids, dealing from his home a block from a high school.

All went pretty well until a 13-year-old tried to use a bogus $100 bill to buy weed.

When Saelee found he had been duped, a car chase ensued.

Portland police said the 13-year-old was in one car with two other people and Saelee in his own.

When Saelee caught up, he fired a .38-caliber bullet through the rear window.

The shot came within inches of the head of the 13-year-old, sitting in back, and hit a metal headrest support, narrowly missing a woman sitting in front.

"A quarter inch either way, and she could have been dead," said Sgt. Dave Anderson.

Police say they had many witnesses and 9-1-1 calls, but it still took days to crack the case. Initially, the victims didn't want to cooperate, they said.

Last week in Multnomah County Circuit Court, with his mother crying and his siblings and friends there to watch, Saelee pleaded guilty to attempted assault with a firearm. He was sentenced to five years in prison. He probably will serve his time at MacLaren Correctional Youth Facility.

Detectives say that drug dealers with guns are usually at least a few years older than Saelee, who had little adult supervision.

"I'm just happy in this one that no one got killed," said Detective Mike Frome.