WILKES-BARRE, Pa. (AP) — A man who police say fired a semi-automatic rifle at officers in the parking lot of a northeastern Pennsylvania shopping center underwent surgery Sunday after being wounded by police, leaving authorities unsure when he will be ready to make a court appearance.

Trooper Ed Urban said it may be a couple days before Scott Lee Sargent, 31, of Shenandoah, can be arraigned on charges that include trying to kill law enforcement officers.

Urban said Sunday investigators have been getting more information about a possible motive, but he declined to release those details.

"There are still things being cross-checked, so I wouldn't want to come out and pin it down publicly at this point," Urban said.

Sargent was being guarded by a trooper inside his hospital room, Urban said.

"We have to sit next to him for every minute of the day until the judge arraigns him, and he becomes the custody of the county prison," Urban said.

Police said Sargent fired at the officers who responded to 911 calls about gunfire outside a Wal-Mart, where several vehicles were struck by bullets on Saturday.

He was struck in the abdomen and thigh, but no one else was injured.

Sargent also faces charges of assaulting law enforcement officers, aggravated assault, being a convicted felon in possession of a firearm and reckless endangerment. The charging documents were not available Sunday, pending Sargent's arraignment, where bail will be set. Urban said that could occur Monday or Tuesday.

Urban said investigators identified the officer who is believed to have shot Sargent, but they are not naming that person or the department.

Police have spoken with a woman who was with Sargent.

"We do have a person he was traveling with identified," Urban said. "They have been interviewed, debriefed and we are following up on the information that person provided to us."

Businesses, including a Wal-Mart that anchors the shopping center, were locked down during the gunfire.

Tina Wagner, an assistant manager at Wal-Mart, said there no interaction between the shooter and people in the store.

"We kept all our associates and customers safe," she said.