Police have failed to prove that a self-confessed night raider of parking meters was the skilled thief behind more than 170 hit jobs on Christchurch machines.

But Brent John Davie was still jailed for a year today after a judge found he was probably responsible for at least 30-40 thefts, totalling anywhere from $20,000 to $35,000.

At Christchurch District Court, Judge Kevin Phillips said the police prosecution had fallen well short of proving that Davie was responsible for the 178 thefts between December 2018 and May 2019 – totalling more than $53,000 in cash and $42,000 in damage - that he was charged with.

And that was despite evidence from a technician contracted to Christchurch City Council to maintain and repair its parking meters, who had to repair the 178 targeted parking meters.

The technician had felt certain that only one person was responsible for the raids due to the "exact nature of the entry".

Davie earlier admitted that, under the cover of darkness, he would cycle into the Christchurch CBD with a jemmy bar tucked up his sleeve.

The 46-year-old would force open the cash door of meters – often around the Avon River and hospital area - remove the cash tin, and disappear.

Davie said he was stealing to feed his Ritalin, meth and gambling habits.

When police raided his Christchurch home, they found 11 empty cash tins taken from parking meters.

Another dumped cash box handed in by a member of the public was found to have his fingerprints on it.

CCTV footage taken from secret cameras installed by police hot on his trail was played in court today and showed Davie raiding two meters.

After watching the film, Judge Phillips concluded that he was "skilled" at breaking in to the machines.

And he pointed to the technician's evidence that found it was the same person raiding the meters every time.

After Davie's arrest, there was a quiet period where there were no parking meter thefts, the court heard.

Thefts that have happened since have been done with a more "violent method of entry", leaving council officials to conclude that a different perpetrator was at large.

But while in a police interview Davie had admitted to the "majority" of thefts, it wasn't clear that the majority amounted to 178.

"I think the case has been very badly investigated," Judge Phillips said.

Although he found that Davie had been behind "a great number" of thefts – certainly more than the boxes found at his house – it was "impossible" to say the exact number and the exact amount taken.