The president of the Peace Officers Research Association of California says the board voted Thursday to withdraw its $50,000. He says the conditions for the reward, Dorner's arrest and conviction, do not apply.
Earlier this week, the city of Riverside said it would not pay its $100,000 for the same reason.
Dorner was wanted for killing Cal State Fullerton assistant basketball coach Monica Quan and her fiancé Keith Lawrence. Police say Dorner was also behind the shooting deaths of Riverside Police Officer Michael Crain and San Bernardino Detective Jeremiah MacKay.
Three people who came face to face with Dorner are seeking the $1 million reward.