Spalding searched the car of a man they had seen buying heroin and found a lock knife in the door pocket, a court has been told.
Serges Mitrjuk, 28, of Red Lion Street, admitted possession of the heroin and the lock knife when he appeared before Boston Magistrates Court.
Prosecuting, Nick Todd said police officers saw him buying heroin in his car in Alexandra Road and when they searched it they found the Stanley blade lock knife in a door pocket.
He told them he had been given it by a friend.
The Probation Service said Mitrjuk had been homeless at the time and kept all his belongings in his car but was now in a shared home and had employment. It was said he had been taking heroin daily for three years.
Mitigating, Sonya Bhalla said Mitrjuk had lived in the UK for 10 years and had been having a hard time and was very stressed.
She said he genuinely didn’t realise it was an offence to have a knife in his car as it was normal to have a knife in his own country of Latvia, but as he was homeless he had had to keep all his possessions in the car.
The magistrates ordered Mitrjuk to take six months drug rehabilitation.
He was fined £300 and ordered to pay £170 in costs and charges.