Lateral Thinking Puzzle #1

I have a book of these lateral thinking puzzles. You know the kind. You are given a setup that doesn't make sense on the surface, but once it is explained it works. I decided it would be fun to post some of them. You can ask questions that have a yes or no answer. I'll respond with yes, no, or doesn't matter. Based on the setup and the answers, you need to try to figure out what is going on. Here we go!

Bob, a fifteen year old boy with a record of violent crimes, approached a screened porch. Taking out a switchblade, he cut through every screen panel with large diagonal rips. A police officer drove by in a patrol car, saw what the boy was doing, and was pleased. Explain.