The mother of a 16-year-old Outlook girl who was killed when she answered a knock on the door Thursday night says her daughter was not involved in gangs.

She tells the Yakima Herald-Republic that Diana Lopez was an aspiring veterinarian who liked school, though one of her brothers had served time in jail. The teen was also a mother herself of a 2-year-old girl.

Authorities say the mobile home where Lopez lived was rife with gang activity. Dispatchers have fielded 21 calls involving the residence since 1998, five of them weapons offenses.

Investigators say four people dressed in blue with bandanas over their faces pulled up at the home Thursday night. Lopez was shot once in the side and died on her way to Harborview Medical Center in Seattle.