Videotape Shows Officer Lied

Around 9:30 on Friday night, a bicyclist pedaling down Seventh Avenue veered to the left, trying to avoid hitting a police officer who was in the middle of the street.

But the officer, Patrick Pogan, took a few quick steps toward the biker, Christopher Long, braced himself and drove his upper body into Mr. Long.

Officer Pogan, an all-star football player in high school, hit Mr. Long as if he were a halfback running along the sidelines, and sent him flying.

As of Tuesday evening, a videotape of the encounter had been viewed about 400,000 times on YouTube. “I can’t explain why it happened,” Police Commissioner Raymond W. Kelly said on Tuesday. “I have no understanding as to why that would happen.”

But this episode was not just a powerful crash between one bicyclist and a police officer. It may turn out to be yet another head-on collision between false stories told by some police officers in criminal court cases and documentary evidence that directly contradicts them. And while in many instances the inaccurate stories have been tolerated by police superiors and prosecutors, Officer Pogan’s account is getting high-level scrutiny.

Later that night, Officer Pogan composed a story of his encounter with Mr. Long. It bore no resemblance to the events seen on the videotape. Based on the sworn complaint, Mr. Long was held for 26 hours on charges of attempted assault and disorderly conduct.

Over the weekend, though, the videotape, made by a tourist in Times Square with his family, fell into the hands of people involved with Critical Mass, the monthly bicycle rally that Mr. Long had been riding in.

The availability of cheap digital technology — video cameras, digital cameras, cellphone cameras — has ended a monopoly on the history of public gatherings that was limited to the official narratives, like the sworn documents created by police officers and prosecutors. The digital age has brought in free-range history.

Hundreds of cases against people arrested during the 2004 Republican National Convention collapsed under an avalanche of videotaped evidence that either completely contradicted police accounts, or raised significant questions about their reliability. The videotapes were made by people involved in the protests, bystanders, tourists and police officers.

At the New York Public Library, a small group holding a banner against one of the stone lions was arrested and charged with blocking traffic in the middle of 42nd Street, although video showed they were on the steps, and nowhere near the street.

In another case at the library, a police officer testified that he and three other officers had to carry one protester, Dennis Kyne, by his hands and feet down the library steps. Videotape showed that Mr. Kyne walked down the steps under his own power, and that the officer who testified against him had no role in his arrest. The charges were dismissed; the Manhattan district attorney’s office declined to bring perjury charges against the officer who gave the testimony.

Dozens of complaints were sworn by police officers who said they had witnessed people violating the law on Fulton Street and near Union Square, but later admitted under oath that their only involvement was to process the arrests, and that they had not actually seen the disorderly conduct that was charged.

An assistant to District Attorney Robert M. Morgenthau wrote to the Police Department to stress the importance of officers’ not swearing to things they had not seen for themselves. The prosecutors said the confusion surrounding mass arrests made it hard to bring perjury charges.

The case of Christopher Long and Officer Pogan is shaping up as another example of an official narrative being directly challenged by videotape.

In a criminal court complaint, Officer Pogan wrote that Mr. Long deliberately attacked him with the bike — although the videotape shows Mr. Long veering away from Officer Pogan, who pursues him toward the curb.

The officer said he was knocked to the ground by Mr. Long. Throughout the tape, though, he remains on his feet, even after banging into Mr. Long.

The police officer wrote that Mr. Long had been “weaving” in and out of traffic, “thereby forcing multiple vehicles to stop abruptly or change their direction in order to avoid hitting” Mr. Long. However, in the videotape, it appears that there are no cars on the street.

Mr. Long is due back in court in early September. By then, most of Mr. Long’s bruises are likely to have healed. The prognosis for the truth is not so clear.