A three-hour hostage drama in a downtown Wheaton bank Friday afternoon ended with the lone offender killing himself.

The DuPage County coroner's office has identified the gunmen as Michael R. Long 41, of the 1400 block of Cantigny Way, Wheaton. An autopsy is scheduled for Saturday to verify the cause of death.

Long took 12 people hostage on the ground floor of Wheaton Bank & Trust, 211 S. Wheaton Ave., at about 1:30 p.m. He was armed with a knife and a handgun that he wrested from a police officer outside the bank.

Wheaton police cordoned off the blocks around the bank and, with the FBI and DuPage County Sheriff’s deputies, negotiated the release of 10 of the hostages, which included both employees and customers.

Two hostages were still in the building at 4:15 p.m. when a single gunshot was heard. SWAT officers breached the building and found the suspect sitting a chair in an employee's office, dead from a self-inflicted wound to the head.

Because the investigation is ongoing, police declined to identify any of the hostages or discuss possible motives for the crime.

The standoff began with a police call about a hit-and-run accident in the parking lot of Wheaton Bank & Trust. A police officer responded at 1:28 p.m., and while surveying the parking lot, Long grabbed him from behind and put an open blade to his throat.

He then disarmed the officer and ran into the bank, where he ordered everyone to the floor. Police did not say if they believe Long at any point tried to rob the bank.

The assault on the officer and the ensuing standoff would have resulted in serious prison time for the suspect, said DuPage County State’s Attorney Joe Birkett.

“If this individual had survived, he’d be facing probably the rest of his life in prison,” Birkett said.

Police believe the hit-and-run call was a ruse to draw the officer to the area, said Wheaton Deputy Police Chief Tom Meloni.

The attacked officer, who was only identified as a veteran of more than 10 years, suffered a cut on his forearm during the struggle. He was treated at an area hospital and released.

After Long entered the bank, police, coordinating their efforts from neighboring Kale Uniform Shop, contacted him over the telephone on a landline.

They were in intermittent contact throughout the afternoon with Long, negotiating the release of the hostages two or three at a time.

Police declined to say whether any demands were discussed.

Communications between negotiators and Long broke down before the fatal gunshot. It was the only gunshot fired during the ordeal, Meloni said.

When storming the bank, SWAT teams had to break through locked doors, and they used non-lethal flashbang grenades. The devices, as the name suggests, emit a loud noise and bright light to create a diversion.

After their release the hostages were interviewed by police. Meloni said the process could take several hours, but probably would not last beyond Friday night.

Employees on the upper floors of the bank were never in direct threat from the gunman. SWAT teams escorted them from the building during the standoff, Meloni said.

Throughout the standoff, downtown Wheaton was in a state of lockdown. Cars and pedestrians were rerouted around a several-block area of the bank, and train traffic on the Union Pacific West Line was halted.

Onlookers jockeyed for better vantage points as news and rumors of what happened circulated through the crowds.

“It looked just like it does in the movies,” said Pat Schultz, who was in nearby Washington  Mutual Bank at the time. “Cars were parked in the middle of the street with their doors open, and police were crouched down behind the cars.

Reporters Dan Petrella and Cari Brokamp contributed to this report.