Got distracted near the very end but seems he killed his first wife, seemingly unintentionally when he swung out angrily and knocked the mains radio into the bath. The other apparent potential victim on the list turned out to be the killer of those on the list, and had strung him along having deduced he had a guilty secret and thought this could be useful. But pushed too far the main character struck the killer with the crowbar taking him out. About then I was interrupted but it looked like it turns out, no surprise, he still gets nightmares about the past.
I'll now go read Chris' link.