In 1971, there was, it seems, a surge in bicycle thefts in Washington, DC with nearly 2,000 bicycles stolen. As a response, the police department began a bait bike program to try to break up the "ring" of bike thefts. On August 11, 16-year-old Gregory James Coleman came across an unlocked, parked 10-speed bike. He got on and started to ride away, until he was shot in the back by a plains clothes police officer. Police Chief Jerry V. Wilson found himself in political jeopardy, with 22 black organizations demanding that President Nixon fire him (because at that time the D.C. Chief of Police was a presidential appointment). Nixon didn't fire him, but Wilson did end the bicycle stakeouts.
1971 was the same year the DC Council passed a law replacing mandatory bicycle registration with a voluntary program. That is the same law that made sidewalk cycling legal outside the Central Business District.
The provision permitting 'bikes on sidewalks outside of business districts will be of limited value until the city provides curb ramps, which would be highly desirable not only for bicyclists, but for baby carriages, shopping carts and wheelchairs as well.
The following year registration would be mandatory again, in part due to the shooting. Crime was still a problem. The newly formed WABA wanted the city "to require office building owners to either provide parking for bikes or allow that they be taken into elevators and offices" something it seemed the Council was ready to do.
When that was published the Building Owners and Managers Association went through the roof. So nothing happened on that until the WABA petitions forced hearings [on bicycle theft problems in the District].
The city had mandatory registration for a number of years, complete with a police bike squad. About '5000 bikes were registered out of 100,000 or so estimated to be in the city.
It appears that the city took the path of reinstating mandatory registration and not requiring bike parking. Mandatory registration would remain on the books until 2008, and zoning rules requiring bike parking would come later. Those regulations were updated this year - requiring more parking.
The shooting also led to the formation of the Coalition of Black Community Organizations for Justice. It's all too familiar considering we're still dealing with some of the same issues today as similar shootings have led to the Black Lives Matter movement. In the 1971 shooting the officer, who was black, claimed that the gun went off by accident due to him using the wrong holster. I don't know if he was ever charged or convicted.