Linda Carman and her son, Nathan, set out on a night fishing trip. They don't return. A week later, Nathan Carman is found in an inflatable life raft, but his mother is nowhere to be found.

Now, police say Carman killed his mother and sank the boat intentionally for a $7,000,000 inheritance.

Carman is accused of enlarging holes in the boat, "Chicken Pox," to ensure it sank. The boat's insurer National Liability and Fire Insurance Co., asked a court to deny any insurance claim on the boat following an investigation that revealed Nathan compromised it before the accident. 

The insurer's report states that in "removing his boat’s trim tabs hours before departing on its final voyage, Carman not only failed to properly seal four thruhull holes he thereby opened at the transom’s waterline, but two recent depositions establish Carman enlarged those four holes.”  

This is not the first time Carmen has been eyed for a murder of a family member: He was reportedly named a person of interest in the 2014 shooting death of his wealthy grandfather, John Chakalos. Warrants say that Carman was the last person to see his grandfather alive before the 87-year-old man was found shot to death in his Windsor, Connecticut, home.

Nathan reportedly purchased a gun that was the same caliber as the weapon that killed his grandfather, a multimillionaire developer, and declined to let police know this during questioning. He also declined to take a polygraph test.

Joining Nancy Grace Today:

• Andrew Norris - Maritime Attorney and Consultant, Tradewind Maritime Services Inc. (Old Mystic, CT), TradewindMaritimeServices.com Former Captain, U.S. Coast Guard, 22 years U.S. Coast Guard Attorney, Qualified Marine Casualty Investigator, Maritime Security and Governance Professor, U.S. Naval War College 
• Dr. Kathleen M. Heide, Ph.D. - Psychotherapist, Distinguished University Professor, University of South Florida, Department of Criminology, Author: "Understanding Parricide: When Sons and Daughters Kill Parents" and "Why Kids Kill Parents"  
• Robert Crispin - Private Investigator, “Crispin Special Investigations” CrispinInvestigations.com
• Dr. Kendall Crowns – Chief Medical Examiner Tarrant County (Ft Worth), Lecturer: University of Texas and Texas A&M, Affiliated Faculty: University of Texas Medical Branch
• Bob Audette - Reporter, Brattleboro Reformer (Brattleboro, VT), reformer.com, Twitter: @Bobbleboro