The footage, released by the police, circulated widely on social media and prompted an Amber Alert. It came less than a week after the fatal stabbing of an 18-year-old Barnard College student in a Manhattan park.

In the end, the abduction turned out to be a hoax.

Both incidents have rattled New Yorkers’ sense of security, even though this year is on pace to be one of the safest on record, statistically.

The Manhattan attack

The Barnard student, Tessa Majors, walked into Morningside Park, which is near the Barnard College and Columbia University campuses, last Wednesday after nightfall.

What happened next was pieced together by police investigators, who obtained video from the park, and from remarks made by a 13-year-old who is charged in the case. The Times is not naming the 13-year-old because he is not being charged as an adult.