The chokehold

In the hours after Mr. Garner died, an initial five-page internal report prepared for senior police commanders, known as a 49, did not refer to contact with his neck. The report, as well as the actions of supervisors involved, is part of the review by the New York Police Department, a spokesman said.

Instead, the report quotes by name a witness who described seeing how “the two officers each took Mr. Garner by the arms and put him on the ground.” That same witness, Taisha Allen, later said she told the grand jury on Staten Island that she saw a chokehold. She said the statement attributed to her in the report was not accurate.

Without video of his final struggle, Mr. Garner’s death may have attracted little notice or uproar. Without seeing it, the world would not have known exactly how he died.

The video images were cited in the final autopsy report as one of the factors that led the city medical examiner to conclude that the chokehold and chest compression by the police caused Mr. Garner’s death. Absent the video, many in the Police Department would have gone on believing his death to have been solely caused by his health problems: obesity, asthma and hypertensive cardiovascular disease. The autopsy report, which is confidential, was provided by a person close to Mr. Garner’s family.

“We didn’t know anything about a chokehold or hands to the neck until the video came out,” said a former senior police official with direct knowledge of the investigation, who spoke on the condition of anonymity to protect his access to confidential department information. “We found out when everyone else did.”