Most likely he was the last one to enter and the others in front of him caught the first rounds which gave him time to respond.
I wonder if the Mother knew he had weapons in the house. Not sure the correct procedure, but seems like they police should enter before the locksmith, and get the person evicted out of the house where he can be closely observed. Evicting a person can easily turn volatile...
Do you have a lot of experience in law enforcement? Done a lot of evictions? Had a lot of maniacs come at you with guns blazing? You know exactly from this short article what they should have done? Your expertise is sorely needed by all those clueless cops who have no idea how to protect themselves.
Read the article.