On August 27, 1994, at 0901 hours central daylight time, a BEDE Jet Corporation BD-10, N2BD, overran runway 8L at Spirit of St. Louis Airport, Chesterfield, Missouri, during an aborted takeoff and was substantially damaged when the nose gear collapsed. The Airline Transport rated pilot and passenger were not injured. Visual meteorological conditions existed at the time of the accident and no flight plan was filed. The flight was to be conducted under 14 CFR Part 91 as a local demonstration flight. After accelerating above rotation speed (Vr), the canopy started to lift, the takeoff was aborted, heavy braking was applied, and the airplane departed the runway end at approximately 30 knots. Investigation revealed that the forward canopy lock pin was able to pass below the lock hole lug instead of through it. The canopy lock indicator light operated normally, and extinguished when the pin was in the extended position. There were no gaps around the canopy seal, and no other visual cues to the pilot that the canopy was not locked. Subsequent redesign has incorporated an extended lug which prevents the pin from extending if the hole is not aligned. Match marks were added to provide a positive indicator to the pilot of canopy position. The pilot had generated his personal accelerate-stop distance by adding the available takeoff roll (850 feet), landing roll (1500 feet), and an estimated 5 seconds reaction time at 90 knots (760 feet), to arrive at 3110 feet of required runway. This calculation was predicated upon the abort decision occurring at or before Vr. The runway used was 3800 feet x 75 feet. The parallel runway was 7000 feet x 150 feet. Performance data developed during initial flight testing includes sea level takeoff and landing roll information. Dedicated rejected takeoff and accelerate-stop data is not available, and is not required by existing Federal Aviation Regulations for experimental aircraft. All performance data developed during initial flight test is available to customers.