HOUSTON—More expert witnesses are expected to testify Monday in the case of an accused cop killer.

Juan Quintero’s attorneys maintain he was insane when he killed HPD Officer Rodney Johnson in 2006.

Quintero has pled not guilty by reason of insanity.

Last week, a psychiatrist said Quintero wanted to die, and that’s why he shot Johnson.

Another witness said Quintero fell as a child and suffered brain damage.