(WTNH) – Nathan Carman, the man charged with killing his mother at sea in a plot to inherit millions of dollars, will have to stay behind bars as he awaits trial.

A federal judge denied Carman’s request for release.

Carman has been held since his arrest in May. He was indicted in the death of his mother, Linda Carman of Middletown.

Linda disappeared during a fishing trip off the coast of Rhode Island. Her body has never been found.

He was also charged with multiple counts of fraud.

Authorities also alleged Carman killed his grandfather, John Chakalos, at his home in Windsor, Connecticut, in 2013 as part of a scheme to obtain money and property from his grandfather’s estate, but he was not charged with that killing.