They said it happened at an apartment building on Monroe in Midtown last week.
Rose Mister, who was visiting someone in the building, said she cannot imagine being in an abusive relationship, and is saddened to hear a 17-year-old was hurt while trying to protect her mother.
"The young lady may feel like every man is the same," Mister said.
Investigators said James Mars attacked his live-in girlfriend.
When the woman's teenage daughter tried to intervene, he hit her too.
Andrew Kemp, who lives in the building and works as a security guard, said he sees situations like this far too often.
"Domestics. It's an outbreak right now in Memphis. Something's got to give," he said.
Police said Mars also stole the 17-year-old's purse.
Mister said she hopes women or men who are in abusive situations will see this story and be brave enough to leave and get the help they need.
"Leave them, and if you don't leave them, go to a shelter. Talk to someone. Just don't be abused like that," she said.
WREG was told Mars is being held on a $45,000 bond.