Monfort's lawyers filed their notice of intent in King County Court on Friday.
Monfort is accused of gunning down Seattle police officer Timothy Brenton as Brenton sat in his patrol car on Halloween night in 2009. He's also charged with the attempted murder of training officer Britt Sweeney.
In addition, Monfort is charged with first-degree arson in connection with the October 2009 fire-bombing of four Seattle police vehicles at a city maintenance yard.
Prosecutors allege Monfort was attempting to wage a one-man war against the Seattle Police Department. He was shot by officers during his arrest and is now paralyzed below the waist and confined to a wheelchair.
King County Prosecutor Dan Satterberg has said he will seek the death penalty if Monfort is convicted.