ROSS TOWNSHIP (KDKA) — The shootout between state agents and a drug suspect sent terrified shoppers running for cover.

When it was over Tuesday outside the Big Lots store at Northland Plaza on McKnight Road, the suspect — 31-year-old Omari Thompson — was dead and an unidentified agent from the Bureau of Narcotics Investigations of the Office of Attorney General was rushed to Allegheny General Hospital.

“I expect that based on information I received from the family and officials at the hospital, that he will make a full recovery,” Pennsylvania Attorney General Josh Shapiro said.

According to police sources, two undercover state agents arranged to meet Thompson in the parking lot to buy drugs from him and then place him under arrest in a “buy-bust.”

Those same sources said Thompson grew suspicious and began firing, hitting one agent in the shoulder and leg. The other agent returned fire and killed Thompson, who was pronounced dead at the scene.

Sources confirm that Thompson fired first.

“The Allegheny County Homicide Unit is the independent entity that will conduct the investigation of the officer-involved shooting,” said Coleman McDonough, superintendent of the Allegheny County Police.

WATCH: KDKA’s Pam Surano talks to people who were in Big Lots at the time of the shooting.

County detectives must now determine whether the officer-involved shooting was justified, though by most accounts it was.

Thompson, of Pittsburgh, was a career criminal who had been in and out of jail on multiple robbery, drug, and weapons convictions that stretched back more than a decade. He was most recently released from prison last year.

But the plaza is the site of a daycare center and was crowded Tuesday with shoppers.

Some question whether investigators could have steered this operation to a safer location.

So while day-to-day life returned to normal at this shopping plaza, the investigation into this officer-involved shooting continues to see what lessons can be learned.