Gunshot damage to a window at the house in Blacktown. Credit:Nick Moir "As they left the home they decided to blast shotgun pellets into the building and those pellets injured a 13-year-old girl," Mr O'Farrell said. "Extraordinarily, her parents are not co-operating with police. "What sort of parents whose daughter's been injured in an attack like this will not co-operate with police? "There are families of these criminal outlaws who know what's happened and who by their silence are putting other people at risk."

A 13-year-old girl was shot in the back with a shotgun on Monday night. Credit:Nick Moir Clive Small, the former NSW Police assistant commissioner, said the girl’s family had no-one to blame for the shooting but themselves. ‘‘I’m not suggesting the young girl was in any way responsible, she is a victim,’’ Mr Small said. ‘‘But the people who have caused her to be a victim is the family. The family have to accept responsibility for what’s happened. ‘‘I understand the family’s not co-operating, and they have to realise that this lack of co-operation is putting the family at risk.’’

The reality is that there would probably be a lot more people dead if these people weren’t just such bad shots Gunmen turned up at the home late on Monday night, apparently looking to settle a score with one of the men inside. But when they opened fire on the house after having the door slammed in their faces, it was the man's 13-year-old sister who was hit in the back. Investigators believe the girl's brother, who was known to police, may have links to the notorious Brothers 4 Life crime gang. Mr Small said that during the past 3.5 years when shootings had been on the rise in Sydney, the Brothers 4 Life gang had become increasingly violent.

‘‘It’s clearly over territory and other criminal activity, and it’s also about power for them. I don’t think the shootings are going to stop any time soon,’’ he said. The increase in shootings was also putting the public at risk. ‘‘You have to look at cases where the wrong house has been shot up, or bullets have hit the wrong car, or innocent people have been wounded,’’ he said. ‘‘The reality is that there would probably be a lot more people dead if these people weren’t just such bad shots.’’ The latest incident comes after one man was killed and two were injured in shootings liked to the Brothers 4 Life.

On Sunday, a 27-year-old man named by media as suspected Brothers 4 Life gang member Michael Odisho was found with multiple gunshot wounds at Winston Hills. A man believed to be the cousin of Brothers 4 Life boss Bassam Hamzy was shot dead in Revesby a week ago and another man, Omar Ajaj, suffered multiple bullet wounds in the attack. Police say it's too early to tell whether Monday's shooting was a revenge attack. Neighbours woken by the fracas thought they were hearing thunder or fireworks until the screaming began. Sarn Pulefele, two doors away, said he was woken up by a loud bang.

"At first I thought it was thunder because I'd never heard guns before," Mr Pulefele said. "Then I got up and I could hear screaming. And then I realised someone's been shot." Mr Kaldas would not rule out that Hamzy may have influenced recent shootings from jail. Inspector Dave Lagats from Quakers Hill police station said the thing police had feared had become a reality. Loading

"Our greatest fears have now been reached ... an innocent person, a 13-year-old girl, has now become the victim of this type of senseless activity," he told ABC radio. Megan Levy and AAP