After more than 15 years as a police officer, the past two and-a-half as head of Cromwell police, he has resigned to develop a campervan rental business called The Pod.
"It's a huge change but I'm positive about it and happy about my decision," the 39-year-old said this week.
"I've always been interested in business and I took leave without pay from the middle of December to set this up and see how it went.
"We thought there was an opportunity there, in the campervan rental market, and it seemed a good time to test the water."
He works from his Central Otago home. The Pod has a fleet of four vans, based at Queenstown, with three more soon to be added, and has plans to expand to Christchurch.
His wife Liz, a detective sergeant with the CIB, is also a partner in the business.
The change of career means Mr Williams can do the "school run" with their young son, and be on hand for holiday and after-school care.
He began his policing in Palmerston North, served a stint in Levin and then returned to Palmerston North as a sergeant, focusing on the gang tensions in the suburb of Highbury. A promotion to the rank of senior sergeant followed.
Mr Williams says his time as team leader of the armed offenders squad, based in Palmerston North, was one of the highlights of his police career.
"I loved it. It was full noise. I was working my day job and on call for the AOS, as well.
"In the end though, for us as a family, the shift from Palmy to Central Otago was unquestionably a good move.
"It was probably an unwise career move - but lifestyle-wise, it was a good decision for me and my family, and we have no regrets.
"While I might pine occasionally for the adrenaline rush of being in the AOS, it was high risk and I don't miss the fear that you might not come back from a call-out.
"You see horrific events throughout your career that can weigh on you and you spent much of your time in a constant battle with crims and that too, can weigh you down, so I'm enjoying dealing with people [customers] now who are happy, and nice and polite."
The title for his new business summed up that the vans included all the facilities travellers needed, " so they're like peas in a pod."
It was a competitive market so price and quality were important.
Most of the customers so far were overseas visitors, who landed at Queenstown airport, Mr Williams said.
Many of his friends were in the police and he remained in "full support" of the organisation, but he was happy with the choice he had made.
"There's nothing like the buzz and energy you get from making your living out of something you've created. It's awesome."
Being anonymous as a civilian was also a pleasant change, he said.
"I can walk down the street and not know whether the people I walk past have a criminal background, or if there's warrants out for their arrest."
Asked about the downside of a policing career, Mr Williams said it was sometimes frustrating dealing with bureaucracy and spending time arguing "when you wanted to be out catching bad guys instead".
Police officers were used to having their actions come under public scrutiny and dealing with criticism was all part of the job, he said.
Mr Williams came under fire a year ago after charging a man whose son drowned in Lake Dunstan with careless driving causing the 3-year-old's death.
Ashish Macwan pleaded guilty to the charge and was discharged without conviction.
His son, Aarush, was one of five passengers in a van which rolled into Lake Dunstan, after he left the handbrake off.
Central Otago mayor Tony Lepper was among the people first on the scene who tried in vain to rescue the boy from the submerged vehicle. He questioned the need to charge the boy's father.
Mr Williams described the incident as "an absolute tragedy, and it breaks you, but as hard as it is, you have a job to do."
He remained "comfortable" that it was right to charge Mr Macwan.
"A judge decides on guilt or innocence; the police only decide if there's a case to answer, regardless of the emotions involved."
When Mr Macwan appeared in the Manukau District Court for sentencing in August last year, Judge Charles Blackie said police had a duty to investigate the loss of life and a duty to bring the matter to court.
