A highly respected NT Police officer with more than 25 years of distinguished service to the Territory has been sacked by the police top brass for daring to criticise Commissioner Jamie Chalker and his executive management team in the NT Independent last year.

Sgt Mark Casey was given notice of his termination this morning in a letter from Assistant Commissioner Bruce Porter in which Mr Porter claimed that Sgt Casey engaged in “subversive [conduct] and undermines public and staff confidence in the [NT Police]” when he wrote an opinion piece for this publication in May 2022 that highlighted Mr Chalker’s failings as leader and his breaches of NT Police values in the Constable Zach Rolfe investigation.

Sgt Casey had also raised issues with Mr Chalker’s “authoritarian” approach and was one of the first to call for a vote of no-confidence in the Commissioner last year over the ongoing breaches of the NT Police’s core values.

When officers were provided the opportunity in a member survey last July, nearly 80 per cent of those who responded said they had no confidence in Mr Chalker to continue in the role, with the largest reason listed as his handling of the Constable Rolfe murder charge.

Sgt Casey, who is the father of two, told the NT Independent on Thursday that he was in “shock” about being terminated and found it ironic that he would be the one sacked for not “upholding police standards”.

“It is retribution and continued persecution for sharing what others were thinking,” he said.

“I’ve spoken to literally hundreds of people, civilians, police officers, ex-police officers, and everyone has said it took a lot of courage to speak out about the lack of integrity and applauded me for my actions. I believe I was upholding the standards. Whilst I acknowledge that I breached some general orders, it was for the higher cause of public confidence in the police.”

Sgt Casey added that he was following the police code of ethics when he wrote the opinion piece because he was required to raise issues of integrity and misconduct when it was presented.

“The last time I did that through the proper processes, I was disciplined, so this was the only way to expose that,” he said.

Sgt Casey, who was suspended in May of last year with no pay at first, said he would be fighting the dismissal with the union’s support, but was informed it could take two years.

“I’ve got a mortgage and family to support,” he said. “I’ve got some decisions that need to be made in the short term. It’s very devastating. I was thinking last night of what they could do that would cause the most psychological impact. This would be it and it is probably the action they would take and it seems to be the method they operate under.”

He was not offered the option of resigning.

According to the dismissal letter, Sgt Casey had been “charged” with three breaches of discipline for the opinion piece and that Acting Supt Sonia Kennon – who was involved in the Rolfe criminal investigation – had pursued the matter because she “was not satisfied with [the] explanation provided” by Sgt Casey.

One of the issues Mr Porter said he had considered before determining to dismiss Sgt Casey was “the issues of public interest, which includes the maintenance of public confidence in the police force … and maintaining the need for proper standards of conduct”.

“Including to ensure the confidence of junior members that senior officers uphold and exemplify those standards,” Mr Porter wrote in the letter.

He also claimed that Sgt Casey showed no “remorse” and that he did not apologise for spreading “misinformation” when he shared his opinion, adding that he contributed “harm” to “the morale of members”, attracting “significant negative media attention”.

Nearly 80 per cent of serving officers who participated in the NTPA survey last year said they had no confidence in Mr Chalker. Preliminary results from the latest survey showed this week that 84 per cent of officers had developed an “exit strategy” to leave the NT and that 76 per cent had rated morale and low or very low.

The NT Independent revealed last week that detectives investigating Zach Rolfe disregarded DPP advice about finding an independent use of force expert and that the direction to not pursue an independent expert came from Mr Chalker’s office.

That matter has been referred to the federal Attorney General and Prime Minister by Labor MLA Mark Turner who raised further concerns about the integrity of the police investigation that appeared to show “manipulation of evidence, failure to disclose relevant material and the appearance of a perversion of justice”.

The NTPA has been contacted for comment on Sgt Casey’s dismissal.