An Andover man believed to have stabbed his partner to death with a samurai sword in north Minneapolis last weekend may have been defending himself after an argument between the two turned physical.

Police are exploring the possibility that the 31-year-old, identified by his initials, TTZ, in a search warrant application filed this week in county district court, was acting in self-defense after being confronted about a series of "text messages from another person on (his) phone."

An autopsy, the results of which haven't yet been announced, is expected to make a final determination about what exactly happened in the deadly confrontation.

The Star Tribune generally does not name suspects who haven't been charged.

The argument late Saturday night resulted in the death of Chris Lein, 40, who was found, critically wounded, on the first floor of his home in the 1500 block of Queen Avenue N. by officers responding to a report of an injured man outside the house.

Police also found Lein's partner in the front yard with "significant" stab wounds, the court filing said. He later told homicide detectives that Lein attacked him with a "green knife" after seeing the text messages and that he had "struck (Lein) with a samurai sword during the physical fight," the filing said.

He also "told officers that he requested sleeping pills from (Lein) some time after being stabbed and prior to going outside where he was located," the filing said. "(Lein) provided sleeping pills to TTZ, which were consumed."

Initially, police deemed the killing — which isn't reflected in the city's homicide tally — "a domestic incident," but they are seeking access to computers and laptops found in the house to confirm his account of that night.