Very likely.
The problem is, there have been some high profile stabbings recently. Teachers getting stabbed by pupils and teenagers stabbing each other. On my stats search, I think I read that 50% of knife crime victims were aged between 14 and 17 years old. This is worrying, we dont want our children either doing this or being placed at risk by this. The media picks up the story and it's everywhere. It sells column inches so the papers run with it. Responsible reporting of the facts, doesnt sell as many papers as sensationalist overstating of the facts. It becomes a case of not so much reporting the news as creating the news. People read the papers and become worried, they press their politicians for action to deal with the "epidemic" and laws get passed. It becomes government by an irresponsible fleet street, who's sole concern is selling papers.
Also, as knife and gun crime are such rare events in the UK, every incident gets tons of press coverage. I would think in the US, domestic gun crime doesnt draw so much media attention, because it's more of an everyday event.
But I can certainly understand how looking at the Uk from abroad, you could be forgiven for thinking things were out of control. After all, for a national knife amnesty to be held, there must be a huge problem - right?