Baltimore Circuit Judge Wanda K. Heard knew it would be difficult to find a panel of jurors who hadn't heard about the case of Mark Castillo, who is charged with murder in the drowning deaths of his three children at an Inner Harbor hotel last year.

But if Thursday was an indicator, it might just be impossible.

Jury selection began about 10:30 a.m., when 145 people filed into Room 400 of the Clarence M. Mitchell Jr. Courthouse, two floors down from Heard's usual courtroom and at least two times bigger. She needed the space: Heard had asked for extra people to appear during the selection process in an effort to find people unacquainted with the crime.

But when she explained the particulars of the case - that Castillo is "alleged to have drowned his three children" - a murmur spread through the crowd, which included Robert M. Bell, chief judge of Maryland's Court of Appeals, who was part of the jury pool. And when she asked those who knew "anything about the case" to stand, nearly everyone did, leaving fewer than 20 people seated.

Castillo's case has been widely publicized since the crime was committed in late March 2008.

Police say the 43-year-old Montgomery County man confessed to drowning his two boys and daughter, ages 2 to 6, in a Marriott bathtub and tried to take his own life to punish his estranged wife. A recorded confession, made at the Maryland Shock Trauma Center the day after the killings, was played in court Wednesday.

Castillo's attorneys, both public defenders, have filed a motion to suppress such statements to police, though Heard has yet to rule on the matter.

She expected jury selection to conclude Thursday, but it's taking longer than expected. The process will begin again this morning, and Heard will likely consider the motions to suppress Castillo's statements once she seats a panel.