WILMINGTON, Del. (AP) — The federal cyberstalking and conspiracy trial of the widow and children of a man who killed his former daughter-in-law at a Delaware courthouse began Monday with the judge closing the courtroom to the public for questioning of potential jurors.

Prosecutors also told the judge Monday that they want an anonymous jury in the case, with the names of jurors kept confidential.

David Matusiewicz; his mother, Lenore; and his sister, Amy Gonzalez, are charged with conspiracy and stalking of David Matusiewicz's ex-wife, Christine Belford. They could face life in prison if convicted of stalking that resulted in her death.

Belford and a friend were fatally shot by David's father, Thomas Matusiewicz, in February 2013 at the New Castle County Courthouse as they arrived for a child support hearing. Thomas Matusiewicz then exchanged gunfire with police before killing himself.

Prosecutors claim that David Matusiewicz conspired with his parents and sister over several years to torment and stalk his ex-wife with the intent to injure, harass, intimidate and kill her. They claim that the defendants repeatedly accused Belford in email communications and Internet postings of abusing and neglecting the three daughters she had with David Matusiewicz.

But Thomas Matusiewicz's family members have denied having any knowledge that he intended to kill Belford.

The trial began Monday with Judge Gerald McHugh Jr., over objections from reporters for The Associated Press and News Journal of Wilmington, ordering that the courtroom be sealed while individual members of the jury pool are questioned. McHugh refused a request by the AP to adjourn the proceedings while legal counsel for the news cooperative was consulted.

McHugh suggested that it is routine in federal court for individual jurors to be questioned at "sidebar," out of the hearing of courtroom spectators.

In closing the courtroom, McHugh noted the number of attorneys and other personnel involved. The decision seemed to be based primarily on convenience, rather than any prejudice to the defendants or privacy concerns for potential jurors.

"Treating the entire courtroom as if it were sidebar will result in no greater secrecy than a traditional sidebar conference: it will simply allow frank and fair jury selection to proceed more effectively," wrote McHugh, who described the sealing of the courtroom as simply a "geographic" expansion.

Before questioning potential jurors one by one, McHugh presided over an open session in which more than 60 potential jurors were collectively asked generic questions about their ability to serve, including their knowledge of the case and any participants, and their experiences and beliefs regarding the criminal justice system.

When asked whether they had any prior knowledge of the high-profile case, more than 50 potential jurors raised their hands. Five indicated that they would be unable to be impartial. At the end of the day, roughly two dozen potential jurors were dismissed. "Oh, thank God," one woman sighed as she left. "Horrible," another woman muttered after sitting in the courthouse all day.

Meanwhile, McHugh said he would hear arguments Tuesday morning on the government's request to keep juror names confidential. Prosecutors also are seeking a court ruling on the admissibility of surveillance video showing the scene in the courthouse lobby after Belford was shot. McHugh indicated Monday that portions of the videotape are "problematic" and could be unfairly prejudicial to the defense if jurors were allowed to see them.

McHugh, a Pennsylvania judge, was assigned to the case after all of Delaware's federal judges were recused.

Last year, prosecutors joined with defense attorneys in specifically asking that Judge Gregory Sleet of Wilmington recuse himself. According to court papers, Sleet's name was one of 16 included on what prosecutors have suggested is a "hit list" found in Thomas Matusiewicz's car.

In a case presided over by Sleet, David Matusiewicz pleaded guilty in 2009 to federal fraud and kidnapping charges after he and his mother took his daughters to Central America. Lenore Matusiewicz served more than a year in Delaware state prison for child endangerment for her role in the kidnapping. The Matusiewicz family has said they were trying to protect one of the daughters from being sexually abused by Belford, an assertion that Sleet said had not been proven.