"Widow's Web" by Urusula Curtiss (A Red Badge Mystery)

Some women have a talent for attracting men. But Annabelle Fennister had an additional flair - a talent for murder.Jim Torrant had never met Annabelle when she was married to Martin, his ex-partner. After Martin's strange death, Jim tried to look her up. But Annabelle and her husband's money had disappeared.He followed her cloudy back trail until he caught up with her. But instead of a grieving widow, he found a woman who was waiting for another inheritance from another man in her life who had just died.It was then Jim learned about the second "accident". It was then he met Annabelle's sinister new boyfriend. It was then he discovered a third stiff who had stumbled into the widow's web.