That's what we both would call NOT solutions!!
Britain has a problem with knife crime. But at least you can fight someone armed with a knife. And a mass-scale stabbing is inconceivable. In terms of being killed by a gun, a person is around 100 times as likely to be killed by one in the US as the UK.
Making getting a gun hard to get works. Aside from the asinine second amendment and its even more ludicrous Supreme Court interpretation, the practical problem in the US is moving from too many guns to restrictive licensing. I understand why people who live on the sharp end of nature need weapons. I don't think they are needed in cities.
Tasers are defensive weapons and mostly don't kill the tasee. Perhaps they could be an adequate replacement for folks who fear home invasions. That, or the sort of dart guns they use to subdue animals.