On CBS’s FBI, a seventeen-year-old steals his father’s gun from a locked gun safe at home and attempts a mass public shooting. The message is parents should be afraid of guns in the home even if they are locked in a safe. Others would support banning guns in the home. Since this type of event is indeed possible, this wouldn’t obviously show bias by itself, but CBS’s FBI has no offsetting examples of civilian-owned guns being beneficial.
For other examples of media bias against guns in other TV shows see here.
(FBI S1 E16, aired March 12, 2019)