Other evidence showed that Herrera's Social Security card had been found alongside Rucker's patrol car on the night he was killed. Splatters of blood on the car identified by Carrisalez's friend as the vehicle involved in the shootings were found to be type A blood, the same as Rucker's. Blood on Herrera's pants and wallet was likewise discovered to be type A. Last, a handwritten letter was found on Herrera when he was arrested which "strongly implied" that he had killed Rucker.