If you're not particular about who gets killed, driving a car into a street fair at 70 MPH is pretty effective too. That just happened in the Washington D.C. area within the last couple weeks. Witnesses on the scene recognized the driver and observed that she appeared to be sucking on a crack pipe as she drove into the crowd. The death toll was close to 13 people.
We need to understand these people, control their attitudes, and divvy out a single shot long barrel pistol to them so we can help them to control their destructive mindsets.
It's like methadone treatments, pay for their destructive attitudes and ease them off of their addiction. This way fewer people are at risk, because their mindful promotion of death and mayhem would be contained then.
Of course as to not make them feel so alone with their personal issues, restrict the rest of the public at the same time so they feel that they are a part of society.
My SUV will be taken away when I cold hands are pried from the steering wheel.