Yes, the cops sorted it out. That's how it should be. It should not be the job of self-appointed vigilantes with guns stuffed in places around their anatomy. They would be out for themselves, not the public good.
Guns can be owned legally in the UK. The owner must have a licence. To get one, he must show the police that he has a reason to own a gun, he is a fit person to own one and the gun will be kept in an approved safe or at at gun club. Hand guns have been banned, except for military and specially trained police officers, since the Dunblane massacre:
http://en.wikipedia.org/wiki/Dunblane_school_massacre
Is it a surprise that there was a demand for better gun laws after an incident like that?
Then there was the Hungerford massacre earlier:
http://en.wikipedia.org/wiki/Hungerford_massacre
It occurred to many people that it wasn't quite acceptable that a nut job could legally own powerful semi-automatic guns, take them from his club and shoot up his mother and others in the local town. Common sense prevailed and now semi-automatics are banned. You see, it's impossible always to identify the nut job before he's killed a few dozen people. Then it's too late.
Criminals can still get guns,of course, That can never be completely stopped. However, the incidence of gun crime is low in the UK. It's really comforting to know that, if someone does pull a gun in a mall, there won't be a few dozen wannabe John Wayne's pulling guns from their socks and various orifices and shooting back. One gunman is easier to escape than several.