The 24-year-old woman killed in an alleged stabbing attack in Sydney once shared an online petition calling for an end to sexual violence and harassment.

Michaela Dunn shared a post in 2016 asking for NSW politicians to introduce laws that would protect people from experiencing online harassment, according to Daily Telegraph reports.

“Sexual violence and harassment is never acceptable — take two minutes to read and sign this petition, it’s such an important issue that needs to be addressed sooner than later,” she wrote on Facebook.

Ms Dunn was tragically killed on Tuesday in a Clarence Street apartment she is believed to have rented for sex work. That afternoon, she had met with alleged knifeman Mert Ney, 20, before being found dead with stab wounds to her neck.

Mr Ney is in hospital under police guard and is expected to face charges over the alleged attack that brought the city to a standstill and led to Linda Bo, 41, being stabbed in the back while at a nearby hotel.

It ended when three local workers took on Ney with a chair and a milk crate, holding him until he was detained by police. Ms Bo is recovering in hospital.

Friends and family of Ms Dunn have spoken out about the “beautiful” woman who loved to travel. She had studied at Rosebank College in Five Dock in Sydney’s inner west and then at the University of Notre Dame.

Pictures on social media show her in Sri Lanka, at music festival Coachella, backpacking around Europe and donating school supplies to children in the Pacific.

At some point, Ms Dunn turned to sex work and registered a company called Sure-fire Match Pty Ltd in 2015, the Telegraph reports.

Ms Dunn’s mother described her as a “beautiful, loving woman who had studied at university and travelled widely”. Police said her family “appreciate the support offered by the community” and request privacy over the death of their daughter who was “very much loved.”

Friend Joan Westenberg, who had known Ms Dunn for 10 years, described her as “like my baby sister”.

“I cannot describe how sad and how broken I am at this moment. I loved this kid. She was incredible,” Ms Westenberg tweeted. “I just want to scream right now”.

She also said she “will not stand for her to be attacked as a sex worker”. “She was working. She deserved to be safe while she worked,” she wrote. “Her job does not make her a lurid story. She was a person and now she is gone.”

Police have established Ney made phone contact with Ms Dunn ahead of his appointment and are working to piece together his movements leading up to the alleged attack.

NSW Police Commissioner Mick Fuller said the long-term investigation would take into account up to two years of Ney’s apparently troubled life.

“We need to backtrack his history, not just the last 48 hours, but the last, potentially, two years,” he said.