Mark Castillo, who is trying to plead guilty to drowning his three children, will be transferred from the Baltimore City jail to the state’s secure psychiatric hospital, a judge ruled Wednesday.

Baltimore City Circuit Judge Gale Rasin granted a 30-day extension to the state Department of Health and Mental Hygiene to have Castillo, 41, of Rockville, evaluated at Clifton T. Perkins Hospital Center in Jessup.