He's been to New York. He's seen the evidence for himself. That's the whole point. Zero tolerance isn't about ending crime, it's about containing working class communities and keeping the poor off the streets. In New York the streets are free of litter, because welfare recipients are forced to clean the streets as part of the Workfare programme and street cleaning is the only option on offer to them.
Homelessness is a crime in New York.
Some of them in New York went to live in shanty towns under the boardwalks at Coney Island. In the UK the average life expectancy of a rough sleeper is 43. But solutions to homelessness that don't involve policing solutions cost money. The price of peace of mind comes expensive if you are talking hostels that don't have to be closed down because they are more dangerous than the streets themselves. Read my lips.