Top investigator Detective Inspector Tom Fitzgerald heads offshore

Canterbury's top investigator is moving to an overseas role focusing on transnational crime and terrorism.

Detective Inspector Tom Fitzgerald, 52, has played a part in more than 100 homicide inquiries and built a reputation as a leading suspect interviewer in a career spanning more than two decades.

He has held the dual role of crime manager in the Canterbury and Southern districts, maintaining oversight of all investigations in both areas.

That's about to change.

Fitzgerald is moving to Canberra to work as a New Zealand police liaison officer — a four year role with a focus on transnational crime and terrorism.

He starts in early October.

"I love this job [district crime manager] … but I wanted to have a look at the international side of policing and broaden my experience and knowledge and this is a fantastic opportunity to do that."

It's understood Detective Inspector Corrie Parnell has been provisionally appointed as Canterbury's new district crime manager. Detective Inspector Steve Wood has been appointed to the role in Southern district.

Fitzgerald's career with police began on the beat in Wellington in 1991 after graduating top of his class at the Royal New Zealand Police College.

He moved to Canterbury two years later and joined the criminal investigation branch (CIB) as a detective constable.

"I always had a passion and a belief that it [being an investigator] would be something that I would be good at.

"The drive for me was the interest in solving crime and being part of that process and doing what's right."

Fitzgerald rose through the ranks quickly and became a detective inspector in 2006. Five years later he was appointed to the role of Canterbury district crime manager.

Fitzgerald said he had played a part in more than 100 homicide inquiries, including Operation Tam — launched after Ben Smart and Olivia Hope disappeared in the Marlborough Sounds on New Year's Day, 1998.

He was the arresting officer in the case and interviewed Scott Watson, the man later convicted of murdering the pair.

Fitzgerald was reluctant to talk about Operation Tam while he was still working for police, but said he was "absolutely" comfortable with the outcome.

"It was a very basic, well put together evidential case."

The rape and murder of deaf woman Emma Agnew in 2007 and the killings of Tisha Lowry and Rebecca Chamberlain, found beneath the floorboards of the 'House of Horrors' in 2009, are among investigations he has run.

"People who work for me on homicides know that it's all or nothing. It's a gold medal event. I don't tolerate second best."

Any case that remains unsolved "digs in my side and doesn't go away".

Fitzgerald is known for his work in organised crime and covert investigations. He is regarded as one of the best suspect interviewers in the country.

Fitzgerald said he still had many years left in the police and hoped to return to Canterbury after his stint in Australia.

Canterbury district commander Superintendent John Price said Fitzgerald was "instrumental in positioning the police district as one of the best performing CIBs in the country".