In the US, fearing outbreaks of civil disorder after 9/11, the US federal government ploughed huge amounts of money into equipping and training rural and suburban police with kit and tactics more suited to urban SWAT teams, if applicable to police at all.
Simultaneously, recruitment was increased, but minimum acceptable standards were loosened or ignored. Hint - this also happened in the US army during the Vietnam war, and there's a direct link from lowering recruitment standards to the plot of many an Oliver Stone film. The result was that police forces got filled with bullies, power-trippers, gun nuts, bigots, opportunists and, I'm sure, some decent people. All taking to heart the following bit of lore from The Wire:
A patrolling officer on his beat is the one true dictatorship in America. We can lock a guy up on a humble, lock him up for real, or we can say, fuck it, pull under the expressway and drink ourselves to death, and our side partners will cover it. So no one, and I mean no one, tells us how to waste our shift.
Take out the guns, and you've got plod over here.