The day his daughter died Dr. Burke spent the whole day drinking at his local pub, the Norman Inn. He consumed quite a lot of alcohol, by anyone’s standard. Over the course of the day as he grew more and more inebriated and wrote a letter to his wife, Katherine about the state of their marriage.
On the night of his daughter’s death it was retrieved from the floor in the room which she died. It was first taken by his wife and then given to the police as an afterthought. The letter could be and was used as evidence in the trial.
The letter was used to prove how competent Dr. Burke was competent when the shooting occurred. The letter although rambling and incoherent in a lot of respects was grammatically correct. This small detail was used against the doctor, suggesting that he had sufficient wits about him to knowingly shoot at his daughter. Nowadays that would not have been the case and advanced forensics could have told a different story. The truth was that nobody knew what happened in the room, because no one was in it except for the doctor and his daughter.