Mark Castillo of Rockville has been charged with three counts of first-degree murder and several related charges, The Baltimore Sun reported. His attorney waived his right to appear at a brief hearing Tuesday.

Castillo had a visit with his children Saturday. When he did not return them by 8:30 p.m., his estranged wife, Dr. Amy Castillo of Silver Spring, began calling police.

Investigators say Castillo took the children, Anthony, 6, Austin, 4, and Athena, 2, to the Marriott Camden Yards, where he drowned them in the tub. He told police he took 100 Motrin pills and tried to slash himself but woke up Sunday afternoon after passing out.

"I know what I did was bad," Castillo allegedly told paramedics. "I did it. I

drown the kids last night around 6 p.m."