Stories like this seem to be quite common -- some badge-wearer uses his position to profit by selling guns to prohibited possessors.
https://www.latimes.com/california/story/2019-07-18/customs-agent-at-long-beach-port-admits-selling-guns-illegally
https://www.latimes.com/california/story/2019-07-18/customs-agent-at-long-beach-port-admits-selling-guns-illegally
Gun-running Long Beach customs agent had 41 machine guns stashed at home