abstract
bars
bed
behind
building
cage
caught
cell
concept
convict
crime
criminal
crooked
custody
depressed
despair
grey
grunge
inside
iron
jail
jailbird
locked
macro
metal
metallic
nail
nobody
object
pattern
penitentiary
person
prison
prisoner
punish
punishment
sad
shapes
shiny
silver
sitting
steel
strong
symbol
tool
wall