Aurora police are investigating the owner of a pit bull that attacked a woman and her granddaughter while they were visiting a home in Aurora, and probing whether the owner knew that the dog was vicious.Dorothy Rugg, 62, was seriously injured with bites to both of her arms and a leg. She is currently hospitalized in fair condition. Her 20-year-old granddaughter, Bobbi Mitchell, was released after being treated for bites to her neck and hand.Police officers had to shoot the dog through the front screen door after it continued to attack the women inside the home, despite being repeatedly stabbed with a kitchen knife.Police said the dog's owners were renting the home at South Nucla Way and South Buckley Road but the dog was not registered there. The home was being rented by a couple who lived in the house with their two kids -- ages 2 months and 18 months.Aurora investigators said if anyone knew that the dog was dangerous, they could face criminal charges, especially because very young kids were in the home and they were at risk.The two kids were being watched by a babysitter who was also taking care of her own 3-week-old infant when the attack occurred."We will certainly look at whether or not the children were placed in harm's way, and if anybody knew this dog was dangerous and had this dog around these very young children," said Detective Bob Friel. "Really, our focus is we're trying to determine whether anybody knew that this dog was vicious. At this time, there's no indication to believe that this dog has a history of being vicious in the past."Neighbors are angry that they were put at risk by the renters and their dog."I don't know them but I'm angry because they put our children's lives in danger," said upset neighbor Dalene Settle.The owner of the Aurora home, real estate agent Paul Inger, said he doesn't know who is living there with the dog. He said he is shocked about what happened and will talk to neighbors."They should probably screen them a little better. Find out where they're from or what kind of background they have ... Certainly, if they've got pit bulls with them," said neighbor Richard Vitamvas.Police said they received a call about a dog bite around 1 p.m. after neighbors heard a loud scream and saw the 75-pound dog biting the women.Officers arrived and shot the dog once to end the attack, then shot it again to end its suffering.The dog is not registered at the address where the attack occurred but police do not know if it may have been registered elsewhere.The City of Aurora restricts ownership of certain breeds, including pit bull terriers.