Callum Le Poidevin, 21, of Skins Lane, St Peter Port, denied possessing a firearm and an article with a blade or point in a public place, claiming there were legitimate reasons for them to be there.
When he appeared in the Royal Court, he admitted two counts of possessing a synthetic cannabinoid and one of failing to provide the unlock codes of two mobile phones to police when subject to a notice served by them to do so.
His explanation for the knife was that he was working long hours as a floor layer and used it for cutting open boxes.
The air pistol had been there to make sure that nobody else got their hands on it, he said.
The jurats found him guilty of the pistol charge unanimously and by a 7-2 majority on the lock knife.
Crown advocate Chris Dunford told the court that details of the offences to which the defendant had pleaded guilty might assist the court when dealing with the other matters because it was the prosecution case that the facts were interconnected.
On 11 November, at about 12.30am, officers went to Le Poidevin’s home to carry out the search. He was in a white Ford Fiesta outside.
The air weapon was on the floor behind the passenger seat. It had a magazine feed which contained white ball bearings.
The knife was in a small compartment next to the steering wheel.
Also seized were two balaclavas – one of them concealed in woofer speaker – and a pair of gloves.
There were cardboard boxes containing plastic dropper bottles and pipettes. Traces of a synthetic cannabinoid were found inside a cigarette packet.
In his bedroom they found three plastic bottles containing a total of 5.8grams of the cannabinoid and some digital scales. One mobile phone was recovered from the bedroom and another from the car.
In a subsequent search of his bedroom £3,700 in cash was found in a bag hidden behind a cabinet.
Le Poidevin, who appeared from custody, was arrested on suspicion of being concerned in the supply of controlled drugs.
He told the court that he was in the car when police arrived because he had been moving cars around to help other members of his family.
He denied that a balaclava had been hidden in the woofer speaker, but said it must have been in the boot and he was not aware of it, which was why there was another one in the front. He used a balaclava and gloves when riding his motorbike in cold weather.
He had bought the plastic bottles, pipettes and funnels online. They were very cheap and could only be bought in bulk. He used them for handling drugs that were for his own use.
The cash, he said, came from selling motor vehicles and wages. He did not like putting money in the bank as it made it too easy for him to buy things online. It was hidden because he did not want it to be stolen.
His advocate, Paul Lockwood, asked him to explain what was happening in a telephone call recorded in prison in which he was telling another person where there cash was.
Le Poidevin said he had been asking a friend to buy Christmas presents on his behalf for other people as he was unable to do it himself because of his incarceration.
He will be sentenced for all matters next month [25 Oct]when a probation report has been prepared.
No application for bail was made.