The Vermont man accused of murder on the high seas will remain behind bars as a federal judge denied Nathan Carman’s request to be released while awaiting trial. Carman is charged with killing his mother at sea in 2016 and also charged with fraud in the 2013 shooting death of his grandfather. He has been in jail since his arrest in May.

District Court Judge Geoffrey Crawford denied the motion for release, saying Carman is a serious flight risk. Judge Crawford also says Carman lacks a strong connection to family employment and the community and that he is concerned about Carman’s gun history.

The defense argued that Carman is mentally unstable and not a threat to flee and Carman’s lawyers are arguing that the evidence against him is weak and that other family members would have had more motive to kill.

Carman has pleaded not guilty to his mother’s death and has denied any involvement in his grandfather’s death. His next court appearance is expected to be around Labor Day.