The man thought it was strange that three people in a minivan would be at his business before 4 a.m. Tuesday.
He also thought the trio were siphoning gas from a vehicle at the business in the 8100 block of Highland Place in Vernon, and called police.
RCMP officers arrived on the scene and arrested the three people, two women and a man, for siphoning gas.
The three, all from Kelowna, were taken into custody. Two were released on promises to appear in court. The third was held for court related to other matters.