Russell St bomber could be released from prison despite additional murder

The man who bombed Melbourne's Russell Street, killing a policewoman and injuring scores of people, could be released for time served despite doing no extra years for killing a fellow prison inmate.

In 1988 Craig Minogue was sentenced to life in prison with a non-parole period of 28 years for detonating a car packed with explosives outside police headquarters in Melbourne.

Constable Angela Taylor, 21, was killed by the blast and another 22 people were injured.

Minogue is expected to make a plea for parole based on his clean prison record over the past 20 years despite killing a convicted murderer shortly after he arrived at prison — a murder for which no additional years were added to his sentence.

Minogue was given a concurrent sentence of 27 years for using a pillowcase stuffed with weights to bash vicious killer Alex Tsamakis to death at Pentridge Prison in July 1988.

The Herald Sun reports senior investigator of the Russell Street bombing, Gary Ayres, said the bombing was enough to keep Minogue behind bars and the prison murder only doubled down on this.

"It (Russell St) is the worst crime we've had. They didn't give a stuff who they killed and then he's killed again," Mr Ayres said, describing Tsamakis' murder as a "freebie".

"It's a free hit. He hasn't paid for a murder. Don't let him out," he said.

Since entering prison Minogue has completed university degrees and a PhD as well as created art.

He is also a suspect in the 1992 murder of Glenroy teenager Prue Bird, 13, who was potentially killed because her grandmother was in a relationship with a key witness in the Russell Street bombing trial, Paul Hetzel.

However, the teen's murder cannot be factored in any decision made by the parole board.