RICHMOND (KRON) — Police found an illegal marijuana grow operation after arresting three people in Richmond last month, according to police.

On Feb. 18, officers responded to calls that four people were walking on the rooftop and climbing into the window of a home in the southern part of the city, police said Monday.

As officers arrived, the four immediately fled from the home and into the backyard.

Police surrounded the yard and apprehended three of the four suspects, one of whom was in possession of a gun. The fourth is still at large, according to police.

When officers searched the home, they found 250 marijuana plants.

Anyone with information about the case is asked to call Richmond police at (510) 233-1214.