How the Toronto serial killer of gays went unnoticed for years.

The property where police say they recovered the remains of several bodies from planters connected to Bruce McArthur in Toronto, Canada, on 3 February. Photograph: Rob Gilles/AP

A friendly gardener and mall Santa, McArthur may also have been the worst ever serial killer of gay men. Did police turn a blind eye?

When the biggest forensic investigation in Toronto history began, it was still possible to be blind to the full extent of the horror…