They did not do so. The bullet is an important piece of evidence, Bell says, because private testing showed signs of lead in a dent in the trim around the garage door, near where his son was shot.

Michael Bell Sr. initially announced a $100,000 offer in November but said Monday he felt he needed to put more pressure on city leaders who have refused to turn over the bullet.

Thirty feet 9 inches long, 10 feet 8½ inches high and 28 feet from wingtip to straight-razor wingtip, the Bell X-1 looked exactly like what had inspired its designers: a .50 caliber bullet.