Neighbors heard four or five gunshots and a family member found the bodies inside the apartment.
"I just heard a couple gunshots and I heard everyone started freaking out and grabbing their kids and taking them inside," said neighbor Marybeth Beaudrie.
Christopher Balzer, 10, and his 49-year-old grandmother, Sherry Multop, were two of the three people who were found dead at the Marsh Creek Apartments in the 25000 block of Marsh Creek Boulevard.
"My niece called me. She found the bodies and I just came running over here as fast as I could," said Tammy Garcia, the victims' sister and great aunt.
The third person found dead is Multop's 54-year-old boyfriend, according to Multop's family.
"She was a kind-hearted person. She helped anybody that needed help. She would give the shirt off of her back. He was your normal little boy. He liked to go out, ride bikes and play video games," said Garcia.
Garcia is Multop's sister. She said their mother also was inside the apartment during the shooting, but she was able to get out.
Police believe they know who the shooter is, but they can't definitively say who yet. However, police did find a gun inside the home. The gun and other evidence have led police to believe this was a double murder-suicide.
"You don't want to believe it's your family. You want to believe you just see something on the news like that. It's terrible," said Harold Garcia, the victim's brother-in-law.
Christopher Balzer was a 4th grade student at Garfield Elementary School in Wyandotte. The family had just moved from Wyandotte to Woodhaven.
A GoFundMe account was created to help with funeral expenses.