From the judgement
"As to the inherent probabilities, the defence is entitled to say this. If Mrs Kissel had indeed planned to drug Mr Kissel into a defenceless state with a view to battering him to death, she would surely have realised that drugging Mr Tanzer, too, would greatly increase the risk of detection."
and
"In other words, could it be that she did lace the milkshakes but only with a view to calming Mr Kissel down – as she said that she had done in the past – and thinking that the effect on Mr Tanzer would not be very noticeable? "
Of course there is also the baseball bat
"245. The prosecution says that the baseball bat appeared in mysterious circumstances well into the trial. Called by the defence, Mrs Kissel’s half brother Dr Brooks Keeshin gave evidence of finding the baseball bat lying on the floor behind a chest of drawers in the master bedroom when he visited the flat with Mrs Kissel’s solicitor Mr Simon Clarke on 9 November 2003. That was one week after the killing. It followed the release by the police of the premises which they had at one stage kept sealed as a crime scene. Dr Keeshin said that he and Mr Clarke examined the baseball bat but noticed nothing on it. Then, Dr Keeshin said, Mr Clarke placed the baseball bat inside a pillowcase. Dr Keeshin’s understanding was, he said, that Mr Clarke would take the baseball bat to his office."