The province's special investigations unit has been called in to Hamilton, where five people have been injured in a stabbing incident.
Police were called to two apartment buildings in the area of Melvin and Parkdale Aves on Saturday night.
Police say a 60-year-old woman and 37-year-old man were stabbed multiple times.
Two other people got minor injuries.
The suspect was also injured, which is why the SIU has been called in. There are reports that a taser and rubber bullets were used during the arrest.