A cold case team of 37 police officers has been assembled to investigate the state's most puzzling unsolved murders, NSW Police Minister David Campbell says.
The Unsolved Homicide Team will have a Sydney metropolitan unit and regional teams in Newcastle, Tamworth and Wollongong.
They would try to close the book on some of the more notorious cases to "give families closure and see justice done", Mr Campbell said.
"I hope this will be a welcome relief to those families who struggle constantly with their loss and the unanswered questions," he said in a statement.
Detectives had reviewed more than 400 unsolved cases and identified almost 200 which have "avenues for further investigation", he said.
Some older cases might benefit from developments in modern DNA technology, Mr Campbell said.