“I couldn’t believe he came back — to the same spot,” Mercer said.
In a way, it made some sense. Most offices on the second floor of Building 197 required specialized key cards to enter. The third floor was the first place where there were nooks and crannies where someone could wander.
Halfway down the west side of the building, where the looming smokestacks of the power plant next door can be seen through the windows, the gunman began to make his own last stand, sometime around 9 a.m.
“He was next door, through a little gypsum wall. He was moving furniture,” Mercer said. Mercer knew the office number. He e-mailed the coordinates: 3(W)20820.
Within minutes he could hear police. And then an eruption of gunfire.
“It was a fierce, major gun battle. Bullets were flying through my office, over our heads, and kept going for minutes,” Mercer said. “Then, I heard ‘shooter down, shooter down.’ ”