A bank was robbed by a lone gunman who escaped with an estimated $1500. After changing cars at a nearby motel, the robber disappeared. D has steadfastly maintained that it was not him. A federal grand jury charged D with three counts of violating 18 U.S.C.A. § 2113(a), (b) & (d) (Supp.1976). A friend of D's' named Dennis Coffie, who bears a remarkable physical resemblance to D, pled guilty to having been the lone gunman in the Florida robbery. D has been tried twice. The first trial ended with the declaration of a mistrial after the jury announced its inability to reach a verdict. A fortnight later, a second jury found D guilty as charged. P introduced evidence that D fled from FBI agents on two occasions. Three weeks after the robbery, D called Dunn on the telephone and asked her to bring some of his clothing to the Fashion Square Mall. After she arrived at the shopping center, she noticed Agents Shields and Miller in plain clothes waiting nearby. When they asked her whether she intended to meet D, she lied, but they guessed her true purpose. A few minutes later they spotted him some distance off, and after one of Dunn's daughters revealed D's identity, Agent Miller ran toward him without identifying himself in any way. D bolted into the shopping center and disappeared. In California, two months after the Florida robbery, agents decided to close in while Coffie and D were riding a motorcycle. Special Agent Callie, who was approaching Coffie and D from the opposite direction in an unmarked car, suddenly crossed over into their lane of travel and drove straight at them. Coffie swerved but was unable to avoid a slight collision. The motorcycle came to a stop approximately one hundred feet past Callie's car. Agent Hanlon, who was not in uniform and had been following Coffie and D in another unmarked car, pulled up alongside the motorcycle. He testified that as he arrived Coffie moved 'about three feet' to the front of the motorcycle and that D moved a similar distance to the rear. Hanlon then emerged from his car with his gun drawn, identified himself as an FBI agent, and informed Coffie and D that they were under arrest. He also testified that he believed that Coffie and D were beginning to flee at the time of his arrival 'because they were I would say approximately fifty feet from where they alighted and moving one was moving in one direction, and one was moving in the other direction, and my own interpretation at this point would be that they were moving away from the bike.'