A man in his forties remains in hospital, but police said his injuries are not life-threatening.
Police said they found a handgun in the home but no other suspects, despite earlier reports from witnesses that as many as two people had forced their way into the building.
It is not yet clear if investigators are looking for a second suspect in what appears to have been a home invasion.
Several homes and a daycare evacuated
Longueuil police learned of the incident just before 10 a.m. when they received a call about a man outside the home who was injured.
They found a man and a woman at the house. Police said the man had been beaten on the head with a blunt object.
Police evacuated several nearby residences and a daycare, secured a school in the area and sealed off a large perimeter, including a stretch of Marie-Victorin Boulevard, because of concerns armed suspects remained in the building.
"The police who came [to our door] told us to hide in our basement," said Isabelle Lavoie, who lives across the street from the home where the incident occurred.
Longueuil police constable Marc David said when investigators arrived, they questioned a man on the scene, believing that he was a witness. He was later arrested as a suspect.
"We're still trying to find out exactly the relationship between the suspect that we arrested and the victim," David said.
David said the man was known to police.
Police declared their operation over at 2:30 p.m. and allowed people to return to the area.
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