Australian Border Force commissioner Roman Quaedvlieg. Credit: Alex Ellinghausen Premier Gladys Berejiklian led the tributes to the outgoing commissioner on Thursday, saying he had driven the state's crime rates be among the lowest in the nation and that his "legacy will live on in the NSW police force". "I don't think I can thank him enough for his leadership of the police force ... of reducing crime in key areas but also ensuring we have the finest police force," she said. Mr Scipione signed a two-year contract extension in 2015, which expires in July, to become the longest serving NSW commissioner since Norman Allan held the post between 1962 and 1972. "I walk in the shadows of heroes everyday," Mr Scipione said on Thursday. "This state wouldn't be in the safe position it's in now if it weren't for those men and women."

NSW Police Commissioner Andrew Scipione announced on Thursday he will retire in April. Credit:Janie Barrett The nationwide recruitment process has already begun to find Mr Scipione's successor in the expectation his replacement will be appointed by April. Ms Berejiklian signalled repeatedly that her government expects candidates to apply from outside of NSW as well as inside the NSW police force. Mr Quaedvleig, is one name high on the list of likely applicants, but he declined to comment when asked on Thursday if he would put his hat in the ring for the top NSW policing job. However he's considered well credentialled for the role, with a career that began in the Queensland police force before he worked his way up to senior roles in the Australian Federal Police and the Australian Crime Commission.

He became deputy chief executive of what was then the Customs and Border protection service in 2013, before being appointed head of the Border Force in mid 2015. Under his leadership, the Border Force has taken on a more quasi-police profile, with a distinctive black uniform, firearms training for some officers and limited powers of detention of suspected offenders. Northern Territory Police Commissioner Reece Kershaw has also been touted as a possible candidate from outside NSW. Both Mr Quaedvlieg and Mr Kershaw's candidature are likely to be opposed by the Police Association of NSW who on Thursday implored Ms Berejiklian and Mr Grant to select the "most suitable applicant from the abundant pool of talent" from within the state's policing ranks From NSW it is expected that Mr Scipione's long-time deputy, Catherine Burn, will also apply and if appointed would become the state's first female commissioner.

Ms Berejiklian also would not rule out approaching recently retired deputy commissioner Nick Kaldas. Mr Kaldas resigned in March last year after 34 years on the force but has previously said he would "seriously consider" the top job if approached by the government. Ms Burn and Mr Kaldas were seen as the two most obvious successors to Mr Scipione although both became embroiled in a long-running police bugging scandal and subsequent investigation by the NSW Ombudsman. The Ombudsman handed down findings in December that found Mr Kaldas could face criminal charges for giving "false and misleading testimony" in a secret hearing over the bugging scandal while Ms Burn engaged in "unreasonable" and "unlawful" conduct. Mr Kaldas and Ms Burn have both disputed the Ombudsman's findings.