Jasper Killed the Sheriff

Warning This Section Does Contain Spoilers

This episode's letter from the Sheriff is definitely different from previous episodes. The paragraphs are indented when they weren't before. The salutation is different. The sheriff's seal is different, the horse's tail and mane are white instead of black. Lastly, the sheriff refers to Dr. Cortes as a female when he referred to the doctor as a male in previous correspondence. The Sheriff did not write this letter. If the Sheriff did not write this letter, then who did? The only person that would make sense would be Jasper. But how would he have access to the Sheriff's stationary? Has he killed the Sheriff and some how gotten access to off campus to the Sheriff's stationary? What purpose is there in killing the Sheriff? Was the Sheriff getting too close to finding out what happened with the body in the woods?