It was supposed to be a standard hearing to update a D.C. Superior Court judge on the misdemeanor case of a Southeast woman charged with possession of PCP.

But as Angeline Walker walked out of the audience in the courtroom to the well of the court Friday, something dropped out of her jeans and made a thud on the carpeted floor: a folding knife.

The security violation sent a buzz through the courtroom. Nick Parker, the prosecutor assigned to Walker’s case, picked up the knife and handed it to a police officer.

Judge Robert E. Morin, who is vying to become the court’s next chief judge, gave a slight smile and said, “I think we should pass the case briefly?” — trying to determine whether to delay the case and call it later in the day. Walker’s attorney, Heather Pinckney, who stood next to her client, shook her head in disbelief.

The incident shocked the courtroom. The court has stringent security procedures that require all visitors to go through three levels of security, including X-ray machines and wanding. It can often take as long as 20 minutes to make it past lines of visitors waiting to go through security.

Court spokeswoman Leah Gurowitz said officials were reviewing the incident to determine why the knife had not been detected.

“Every security incident in and around the D.C. courts’ Judiciary Square campus is used to strengthen training of court security officers with the goal of preventing future occurrences,” Gurowitz said in a statement.

U.S. Marshals Service spokesman Dave Neumann said that the knife, a folding one with a blade less than three inches long, is legal and that no charges will be filed. But Neumann said he was “concerned” by the security breach.

He said the screenings are performed by security personnel who are not U.S. marshals. He also said that court security supervisors will investigate the incident, and that the marshals will be informed of what happened and what changes, if any, need to be implemented.

Pinckney, the defense attorney, declined to comment.

After the knife was dropped in court, a U.S. Marshals Service supervisor was called to the courtroom and tried to escort Walker out to ask her questions. But Pinckney insisted that all questions go through her.

Visitors in the courtroom seats watched the incident unfold.

“Seriously? She really just dropped that knife and kept going like no one saw her do it?” said Marion Johnson, 63, who was waiting for a hearing for her nephew.

“They make us just about strip to come in here, and she can walk in here with that? Unbelievable,” added Wilson Jones, 42, who was sitting two rows behind Walker.

It is not unusual for people to carry pocketknives to D.C. Superior Court. But most surrender such an implement to security personnel before they enter the courthouse or, in many instances, stash it in the bushes outside the courthouse and retrieve it later.

Walker’s hearing in the PCP case was called a second time, and another prosecutor had to take over the case. Under professional guidelines, Parker had to remove himself from the PCP case because he was a witness and had picked up the knife.

The new prosecutor, reading from reports, said Walker, 33, was eligible for mental-health court but had not attended the proper sessions for screening. A hearing was scheduled for July 6.