Julie Ann Stewart says her brother was a fun-loving larrikin and "everybody's friend" and it's unfair the murderer remains at large.

"It's not fair. We shouldn't have to be here and somebody else is roaming the streets. They've done this to us. We didn't ask for it. Mark didn't ask for it," she said outside the NSW Coroners Court on Thursday.

"Hopefully karma will get them."

Police on Wednesday offered a $1 million reward for information about 53-year-old's killing in 2018, after previously saying he had no known disputes.

Mr Russell and his sister grew up in Goulburn before being placed into foster care for most of their childhood.

After decades of living rough on the streets, Mr Russell had moved into the Surry Hills unit on Clisdell Street not long before his death.

Neighbours heard talking coming from his apartment on the evening of February 24, 2018, which was not uncommon as he was frequently visited by guests at all hours.

One neighbour recalled hearing Mr Russell saying "f*** off" loudly, but said it was not unusual to hear him yelling and talking to himself.

After another neighbour heard noises from below his unit, he went to speak with the tenant and noticed someone in Mr Russell's home sitting on a lounge, who looked uncomfortable

That morning about 11am, Mr Russell's friend David Albert purchased a bottle of port to drink with him, but became worried when he called out and received no answer.

After climbing through a window, he found Mr Russell laying on his lounge, unresponsive, and with a red pillow on his chest.

He immediately called paramedics, who pronounced him dead.

An autopsy found multiple stab wounds to the chest and neck area.

"Defensive-type" wounds included seven stabs on his right hand and five to his left, while a toxicology report found his blood alcohol level at 0.202 as well as benzodiazepine, methylamphetamine, and cannabis in his body.

Detective Sergeant Peter Smith told the inquest Mr Russell died sometime between 7pm on February 24 and 6.30am the following day.

Mr Russell, along with his associates, were heavy drinkers, did not own mobile phones and were unemployed, which Det Sgt Smith said made it hard for detectives to piece together an accurate timeline of events.

He also said the apartment was difficult to forensically examine as it had never been cleaned, and his frequent visitors meant his friends had "every reason to have fingerprints at the scene".

Deputy State Coroner Derek Lee referred Mr Russell's case to the unsolved homicide unit.

Australian Associated Press