A male victim suffered life-threatening injuries after he was shot in a three-story Mattapan home, according to the Boston Police Department.

The victim, whose name was not disclosed, was taken to a nearby hospital for treatment, spokesman James Kenneally said.

Nobody has been arrested in the shooting, which took place at 551 Norfolk St., and the investigation is ongoing, he said.

A woman, who identified herself only as Paula, said she was a tenant in the multifamily home where the shooting occurred. She said the victim was her son’s friend.

Her son was questioned by Boston police, and said he was on a different floor when the shooting happened, she said.

Ella Torres can be reached at ella.torres@globe.com.