noun, する verb
Arrest and put the criminal in detention and confinement. Get in there, criminal!
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
I heard that the woman was drunk with a miniature Shiba Inu on her lap, so the police, who could not bear to see the situation, took the dog into protective custody and returned it later.