Well, not completely happenstance. But mostly. The description was fairly broad. That’s the point. The cop almost didn’t bother.
He was a teen male between 5’7 and 6’2 and alone...
Wrong. The description was perfect. Age, height, burgundy shirt and the suspect was walking down a street less than a mile from the mass murder scene.
No doubt the second the cop laid eyes on the suspect, he was confident they had their man.
In fact, based on the fact the cops had visited the suspects home DOZENS of times, I would not be surprised one bit if the cop who spotted the suspect walking down the street KNEW the suspect because he had prior contact with him.