Drew is not stupid. He learned from his experience in law enforcement and with previous wives. With wife #1 he learned what it was like to pay child support and not have custody so that never happened again.
He decided not to kill Kathleen with a knife on the stairs. It would have been an obvious homicide, made a mess, and he had not set up an alibi.
It seems to me that he waited, went there at night, used his baton to cause bruises and head wound, drowned her in the toilet, undressed her (forgot the necklace), put her body in the tub, poured oj & put tea in microwave to indicate morning (he would get alibi proof), and took her clothes home to wash in the middle of the night. Next morning he made sure to go somewhere to get and keep receipt (Krispy Kreme). He remembered what was made for breakfast to later coach Stacy during interview and he went to the aquarium to get and keep another receipt.
He decided not to kill Kathleen with a knife on the stairs. It would have been an obvious homicide, made a mess, and he had not set up an alibi.
It seems to me that he waited, went there at night, used his baton to cause bruises and head wound, drowned her in the toilet, undressed her (forgot the necklace), put her body in the tub, poured oj & put tea in microwave to indicate morning (he would get alibi proof), and took her clothes home to wash in the middle of the night. Next morning he made sure to go somewhere to get and keep receipt (Krispy Kreme). He remembered what was made for breakfast to later coach Stacy during interview and he went to the aquarium to get and keep another receipt.