Gold Coast police Detective Superintendent Brendan Smith targeted parents and the community to help change a growing gangster attitude among youths that knife crime was “cool” with teens filming crimes, encouraging violence, and sharing footage on social media platforms.

“It’s beyond belief that people behave like this … the mindset of young people today, that this sort of conduct, it’s appropriate to video it and then populate it through social media,” a clearly frustrated Smith said.

“It’s an incredible indictment on some of the people that are in our community today. It’s about time everyone in the community said enough is enough and we pull these people into line about their behaviour and attitudes.”

Criminology expert, Bond University Associate Professor Terry Goldsworthy, said recent incidents also showed a worrying trend of people not just standing by and doing nothing during a criminal act, but encouraging violence to get it on film.

“It’s a clickbait mentality, where the more gruesome it is, the more confronting it is, the more hits or chance for a sudden moment of fame. They’ll put anything up just to get some notoriety without thinking of long-term consequences,” Goldsworthy said.

Police on Thursday charged two 16-year-old girls with murder relating to the ongoing investigation into the death of 19-year-old Cian English on the Gold Coast.

The girls, both 16, allegedly filmed and encouraged three men, already charged with murder over the incident, to assault, torture and rob English and his friend before English fell from the balcony of a Surfers Paradise high-rise apartment while trying to escape.

Both girls were both charged with one count of murder, one count of stealing, two counts of robbery, two counts of torture and two counts of deprivation of liberty. The three men charged with the Brisbane teen’s murder have faced court and remain in custody.

Police this week also confirmed they were investigating an attack by teens on a 13-year-old girl at a Sunshine Coast playground after footage was uploaded to social media.

In the mobile-phone video taken at Nambour’s Quota Park, a teenage girl filming the incident can be heard telling the assailant, “you’re not even doing anything, punch her in the face.”

Sunshine Coast Inspector Jason Overland said the “disturbing footage” was being investigated by specialists.

Clearly appalled at the behaviour of the alleged assailants in the Gold Coast attack, Smith said the girls’ alleged behaviour in encouraging and filming the attack on English went to the “very core of their attitudes.”

“We need our young people to talk to their peers and say enough is enough. They’re not listening to adults. They think it’s cool. We need to turn that around, we need to change attitudes.

“In my view it’s that gangster attitude that a lot of young people think that it’s cool. It won’t change unless their peers pull them on about their behaviour.”

Goldsworthy said the “shocking” move to film people being subject to violence and posting those violent acts online was a disconnect between what was happening and the urgency to get “gotcha moments” and social media hits.

“These people who are committing offences, or being party to an offence by encouraging or filming and then posting on social media, I don’t think there’s a great thought process going on there. They’re just living in the moment and the moment is filming an assault, and the next moment for them is putting it up on social media and seeing how popular they become by the views, the hits and the likes.”

This article is supported by the Judith Neilson Institute for journalism and ideas