What makes you think it was the Police Chief who wanted/decided to 'hold it back'?
Look further up the command chain.
Oh I can certainly envision the mayor or council leaning on the chief to suppress info but there comes a time to show decision and backbone. It was his people and department being lied about.
He finally put out the store video after five days in spite of the governor and the Just Us Dept. opposition but the lies by Mini-Me had grown into a real monster by then.
The chief should have manned up from the start.