As Leonard John Warwick was being questioned by detectives at a south-western Sydney police station over a series of attacks he allegedly carried out three decades ago, Deputy Police Commissioner Nick Kaldas wanted to send a message.
"If you have been involved [in] ... a murder that may be historic, you need to realise the door will never be closed on an investigation," Mr Kaldas, a former homicide chief, told reporters.
Wednesday's charging of Mr Warwick, 68, followed three years of intensive detective work by the NSW police's elite homicide squad led by Detective Superintendent Michael Willing.
Within that squad exists the unsolved homicide unit, guided by Detective Chief Inspector John Lehman, that was established in 2004 to review cold case investigations.
The unit reviewed the evidence in the Family Court bombings in June 2012, and decided it should recommence the investigation into the series of crimes, including four murders.
A room within Parramatta's police headquarters was dedicated to the case. At any time, between 23 and 35 homicide detectives were working on the investigation under the guidance of the meticulous Detective Chief Inspector Pamela Young and the hard-working officer in charge, Detective Sergeant Matt Russell.
"The tenacity of the detectives involved, the professionalism and commitment that's been shown by the team led by detective inspector Pam Young has been outstanding," Mr Kaldas said.
"This is demonstrated proof of the persistence and focus of the detectives on this team; like all NSW Police Force investigators – they never gave up."
Detectives re-interviewed witnesses and spoke with new ones who had not talked to police before, either because they thought their evidence was insignificant or they were too scared to do so.
New methods and technologies allowed the unsolved homicide squad to re-examine the previously collected evidence.
Detective Superintendent Willing said Wednesday's arrest would not have been possible without the excellent work carried out by police three decades ago.
The crimes were the subject of a joint federal-state police investigation which lasted for five years.
"We have built on the work that they've done," Detective Superintendent Willing said.
"I want to commend those investigators from 30 years ago who were some of the best that we've had and I'm glad to say that their work has been followed through by some of the best we have now."
Detectives on Wednesday appealed for anyone else who has information about the investigation, and who had not yet spoken to police, to come forward.
