NEW ORLEANS (AP) — Authorities in Louisiana say they are in pursuit of 10 inmates — at least one of whom is convicted of murder — who escaped from a New Orleans jail. Another inmate was captured Friday after a brief foot chase through the French Quarter, the Louisiana State Police said in a post on the social media platform X.

Authorities first noticed the 11 inmates were missing during a Friday morning headcount.

One of the fugitive inmates, Derrick Groves, was convicted on two charges of second-degree murder and two charges of attempted second-degree murder last year for his role in the 2018 Mardi Gras Day shootings of two men. Groves also faces a charge of battery against a correctional facility employee, court records show.

Orleans Parish Sheriff Susan Hutson said the department is actively working with local, state and federal law enforcement agencies to search for the escaped inmates.

“We are launching a full investigation to determine how this escape occurred, including reviewing facility protocols, staff performance and physical security measures,” Hutson said. “Any lapses or failures that contributed to this incident will be addressed swiftly and with full accountability.”

Investigators are focusing on an opening inside a cell through which at least one inmate is believed to have escaped into a maintenance corridor, according to one current and one former law enforcement official who were not authorized to discuss the ongoing investigation and spoke to The Associated Press on condition of anonymity.

“That’s how they escaped,” the current official said, adding investigators were reviewing surveillance footage that captured the jailbreak.

The AP obtained a photograph the current law enforcement official confirmed shows the opening in question. A former law enforcement official who worked in the jail for several years said such an opening — of just a few feet — would typically be covered by a sink and toilet that may have been removed in this case.

Louisiana Attorney General Liz Murrill called the escape “beyond unacceptable” and said local authorities had waited too long to inform the public.

“Someone clearly dropped the ball and there’s no excuse for this,” Murrill said in an emailed statement. “My office will do whatever it takes to determine how this happened and make sure that it won’t happen again.”

New Orleans Police Department Superintendent Anne Kirkpatrick said her agency has put “a full court effort” to respond to the escape and are working with the FBI and U.S. marshals.

“It’s more than likely that someone had help and they are not running around in a jumpsuit — but if they are, you’re going to stand out,” she said.

Officers were focused on identifying and providing protection for individuals who may have testified in their cases or may be in danger. One family has been “removed” from their home, Kirkpatrick said.

“If there is anyone helping or harboring these escapees, you will be charged,” Kirkpatrick added.

Associated Press writer Jim Mustian contributed to this report.