Death in the Embassy

How do you prove that something did not happen? How do you prove a negative? This is the conundrum facing Jake Curtis and Vanessa Malone as they tried to prove their beautiful client, Isabella Patrillo, didn't murder her ex-husband. Alberto Patrillo dropped dead of arsenic poisoning at his ex-wife's feet during a gala at the Italian Embassy in Washington, DC. Post mortem tests revealed Alberto had been poisoned over the two months before he died.
The private investigator Isabella hired to look into the possibility of Alberto's unfaithfulness found out Alberto had not only one mistress, but that he had two mistresses. When the PI told Isabella about Alberto's cheating on her, she blocked him her mind and heart. She went to Reno, Nevada to obtain her divorce and returned back to DC three weeks before Alberto's death.
DC police homicide Detective Lieutenant Robert Murdoch is a good cop with one of the highest conviction rates in he department. He is a sometime protagonist of Jake and Vanessa and a sometime antagonist depending on his mood at the time. Murdoch considered the wife, or in this case the ex-wife, the prime suspect in her ex's murder. Isabella maintained her innocence.
Jake's Las Vegas PI friend and former Vegas cop, Linda Hampton, with whom he once had a brief relationship back before he met Vanessa discovered Isabella obtained her divorce three weeks before Alberto dropped dead and she didn't leave Nevada for the six weeks of her residence in Reno and the four days she later spent playing tourist 0in Las Vegas. Vanessa knows of Jake's friendship with Linda, but not of their relationship, or at least he doesn't think she does.
If Isabella didn't murder her ex, then who did? Did Alberto's daughter, Donatella, who stood to inherit her father's wealth, murder her father? Was it one of the two mistresses he promised to marry? Who dun it?
Through interviews with Isabella's daughter and Isabella's closest friends, Jake and Vanessa determined Isabella didn't have the opportunity to administer the poison to Alberto during the day. It was Isabella's nights that proved to be more of a problem. Did Isabella meet with Alberto at night, and if so, did she poison him?
Isabella's Jewish mother suggested that if Jake and Vanessa couldn't prove Isabella didn't meet Alberto at night, then prove Alberto didn't meet Isabella at night. Jake and Vanessa confronted Alberto's two mistresses.
The ex-husband is not the only person murdered in this love rectangle. Tessa Lombardi, Alberto's fiancee with whom he lived when Isabella threw him out dropped dead from arsenic poisoning as Jake and Vanessa knocked on her door. Post mortem tests revealed Tessa died of the same poison that killed Alberto Patrillo.
Jake and Vanessa's investigation led them to a pair of biker bars, a shootout, subterfuge by a waitress, culminating in the chase of an escaped murderer through a busy detective squad room.