The shirt shows a picture depicting Monfort on the front with a blood splatter and a Seattle police badge under the words "Deliver Us From Evil." The back of the shirt quotes Public Enemy's "Fight The Power" and says: "Most of my heroes don't appear on no stamp."
You can find a picture of the shirt via Seattle Crime who first reported this one. Frontman Michael Torres justified the shirt with this statement on a message board:
Over the last week, I saw a lot of support for this dead officer, and a lot people who alledgedly hate the police putting their opinions aside in the wake of this supposed "tragedy".[...] That doesn't excuse the actions of police in general and I refuse to change my opinion on the subject. When police die, I feel that the streets are just a little bit safer. So with that being said, I'm in no way embarrassed that we made this shirt. A lot of people took a stance on the situation....now I'm taking mine.
Some more discussion can be found via Seattle Weekly.