Let's completely sidestep and ignore the issue of news release accuracy or completeness by police departments.
Let's talk about money... I think it's a open question as to whether or not it's necessary for so much money and time be spent on informing the public. It seems to me that it should not be so expensive or time consuming to release facts to the public in a timely fashion.
Media likes to give itself some treats for being so vital to society.
Just a little wrong here or there in the name of profit to ease the heavy burden of having the power to shape opinion.