FAMILIES of homicide victims have joined thousands of signatures on a petition to have charges dropped against high-profile detective Gary Jubelin

Detective Chief Inspector Jubelin, 57, who led the search for missing toddler William Tyrrell, was last week charged with four offences under the Surveillance Devices Act allegedly committed during the investigation.

The petition on change.org was set up by Helen Hagerson, whose son Lucas was stabbed to death in 2004.

"As the mother of a homicide victim, I along with numerous other homicide victims' families know the unending work, time and dedication Gary Jubelin has put into bringing resolve to many victims' families," Ms Hagerson wrote on the petition which in two days has collected more than 8100 signatures.

Among those who were first to sign were Mark and Faye Leveson, after Jubelin investigated the cold case disappearance of their son Matty and was instrumental in persuading Matty's former boyfriend to lead them to his remains buried in the Royal National Park south of Sydney.

"Drop the charges against Gary Jubelin now," Faye Leveson wrote.

"If it wasn't for him Mark and I would be still out in the national park looking for our son Matty's remains.

"His integrity and professionalism is beyond reproach. You have left victims and their families disillusioned and disappointed in the NSWPF and how it is heading. Stop the witch hunt now!"

Mr Leveson said today that they did not think the petition would sway the Office of the Director of Public Prosecutions to drop the four criminal charges but it was a show of support.

"If ever you go to war, he is the guy you want in the trenches with you," Mr Leveson said.

Jubelin resigned in May after being taken off the hunt for William Tyrrell who vanished, aged three, from his foster grandmothers' home in the NSW Mid North Cost town of Kendall on September 12, 2014.

He is due to leave the force next month and has denied any wrongdoing.

Among other signatures on the petition are from families connected to Colleen Walker, 16, Evelyn Greenup, 4, and Clinton Speedy Duroux, 16, from Bowraville's indigenous community who see Jubelin as a hero after he pulled out all the stops to try and get a local man to face trial for all three murders.

The High Court in March refused to hear an appeal against a decision by the NSW Court of Criminal Appeal which rejected the attempt for the man to face a single trial on the murder charges from the 1990s.

"We need this man to stand up for our people. Whatever it takes. He has been incredible in supporting the families of the murdered Bowraville children," one signatory wrote.

Jubelin is due to face court next month.