Bernadette McFadden’s son Eoin was shot as he slept in their house in Kildrum Gardens just after midnight on Monday.
Three masked men burst into the house, and two of them went into the victim’s bedroom.
He was shot in each leg.
The victim was taken to Altnagelvin Hospital for treatment.
“It wasn’t Eoin they were looking for,” Ms McFadden said. She said those responsible should face justice.
“I was up in bed and I heard a knock on the door so I came down,” she said.
“I actually thought at first it was my son, because sometimes he forgets his own key.
“They [the three masked men] then just pushed in… one pushed me into the sitting room.
“The other two went up the stairs and into Eoin’s room and just shot him – they didn’t even ask who he was.”
Ms McFadden said it was “terrible” that these men could just “push their way into” people’s homes.
“It’s disgusting. I am really mad that they can get away with that stuff,” she said.
Police have appealed for information following the incident.