Cmdr. Paul Bauer, 53, was shot to death at the Thompson Center after chasing a man fleeing from tactical officers who tried to stop him, police officials said. Bauer confronted the man, who opened fire as the two struggled, killing the 31-year department veteran, according to police officials and other sources. Bauer had been in the area after attending “active shooter” training, which prepares officers for mass shootings. He also had a meeting with aldermen scheduled for later in the day.