A new report suggests that the Mile High City's police don't arrest off-duty Denver cops for driving drunk unless they are involved in collisions, and a new department policy will help prevent requests for such professional courtesy from being honored.

Since 2005, when Independent Monitor Richard Rosenthal began monitoring police discipline, Denver police have arrested five of their own who were found to be drunk after a collision, he said in his second-quarter police and sheriff discipline and critical-incident report. But none has been arrested solely for driving under the influence.

At the same time, Denver Police Department data show that for about every three of the city's residents arrested for DUI, there is one resident arrested for a collision in which they were found to be intoxicated.

Colorado jurisdictions outside Denver aren't reluctant to arrest Denver cops for drunken driving, the report said. "There has been a 4-to-1 ratio of DUI traffic arrests to DUI arrests ensuing from collisions involving off-duty DPD officers in other jurisdictions."

Based on the 3-to-1 arrest ratio in the general public, it would make sense that roughly 15 Denver police officers should have been arrested for DUI with no collision, the report said.