Precinct 99½
Gnome Alone
A missing garden gnome. The biggest case in 31 years.
In the pilot, Pickle Creek's three-person police department treats a missing garden gnome like a manhunt, only to learn the Chief bagged it as evidence himself.
From the script

Chief BixbyNobody step in the outline. Somebody took Sir Reginald.

Mrs. HollowayForty years on this lawn, Chief. Gone since your hedge inspection Tuesday.

TannerOperation: Gnome Alone. Is this a chase? Tell me this is a chase.

Chief BixbySection 9, subsection B. Everything gets bagged. Bag the outline, Briggs.
Next time: Earl's pillow becomes evidence
Chief Bixby
Mrs. Holloway
Tanner
Earl
Bev