Believe the Police?

SF Gate brings in some good news for the Band:

"After a thorough review of the excellent police report submitted in this matter, which included an extensive follow up investigation, the office of the District Attorney will not file criminal charges in the matter of the damage to the Stanford Band Shak," he said. "We believe there is insufficient evidence for us to prove the case beyond a reasonable doubt unanimously to a jury."

Why do police officers pat themselves on the back in writing? Completely unrelated, but how are they going to spin the UCLA tazer incident?