The Vermont man charged with killing his mother at sea in hopes of cashing in on a $7 million inheritance now faces the possibility of life in prison over the sick scheme.

Nathan Carman, 28, appeared in a federal court Wednesday on multiple fraud charges, as well as for the murder of his mother, Linda Carman, according to court documents.

Carman was found alone in an inflatable raft off the coast of Rhode Island after both he and his mother had gone on a fishing trip. Federal prosecutors allege that Carman had sabotaged the boat prior to taking it out with his mother.

In his initial statement, Carman told members of the Coast Guard that he attempted to rescue his mother but was unsuccessful. However, witnesses testified that they saw him deliberately make the boat unseaworthy.

“Nathan Carman planned to kill his mother on the trip,” reads the indictment.

“He also planned how he would report the sinking of the ‘Chicken Pox’ and his mother’s disappearance at sea as accidents.”

Police also suspect that Carman may have had a hand in his grandfather’s mysterious death in 2013.

John Chakalos was found dead in his Connecticut home after being shot three times in the head. No criminal charges were ever filed against Carman, though police had named him a person of interest and executed a search warrant for the then-22-year-old’s home.

Federal prosecutors deemed Carman a flight risk after finding $10,000 at his home and asked the judge to detain him until his trial.

Prosecutors noted that Carman has history of mental health problems which have gone untreated since he was 17 years old.

Carman faces four counts of wire fraud, three counts of mail fraud and one count of first-degree murder. Carman is set to appear again in court on Monday.