A homeowner can always give police permission to enter his/her home.
The police can also enter your home without a warrant to provide protection:
– to give emergency aid to someone inside
– to protect the life or safety of someone inside if they have a reasonable belief that a life-threatening emergency exists
– to protect the life or safety of people in the home if someone heard a gunshot inside
– to prevent something that may be about to happen, if they have a reasonable belief that their entry is necessary to stop it or to protect their safety or the safety to the public