There's a modification of that saying for Britain and France:

When seconds count, the police are minutes away.  And not armed.
The ranks of police marksmen must be reinforced to meet Islamic State’s ‘theatre of war’ tactics, a top officer said last night.
...
He suggested dozens may be dead by the time special forces and other armed officers were able to confront attackers.

And something I'd not heard before:
Mr Chesterman added that police had considered using automatic weapons, but the risk of killing bystanders was too high.

Many officers are still wielding the Heckler and Koch MP5 – designed more than 50 years ago.

And all weapons available to police fire only a single shot for every trigger pull, as this is more accurate and they must justify every bullet.
As a general thing, not a bad idea: police are SUPPOSED to justify every round fired, and unless there's a lot of training and practice involved, automatic fire tends to be rather messy.  Better a few aimed shots that actually hit, than bursts that mostly don't.

In any case, the main problem is "We don't know when and where the bad guys will strike, and having to wait for an armed officer to show up could lead to a lot more dead bodies."  Much like when those slimeballs murdered a British troop, and the first-responding cops sat around until an armed officer could get there.