London police link 20 unsolved murders

Police in London, Ontario, say they are investigating 20 unsolved murders in the city dating back to 1956. They may all be linked.

The killings continued until 1983. Young women and children were strangled and sexually assaulted.

Police are asking the public to help solve the mystery.

This may be the largest murder investigation in Canada. The case is called Project Angel. Several police officers came out of retirement to help assist with the case.

Police have DNA evidence from every case. They've been working on the case for the past year. They have never held a suspect.