Antonio Hillard was arrested because he matched the description given by a 911 caller, and was supposedly trying to flee when officers arrived at the scene.
After he was convicted of criminal possession of a controlled substance and unlawful possession of marijuana, Hillard appealed claiming that the officers lacked a "reasonable" basis to pursue him--because their information had come from an anonymous source.
On appeal, the Appellate Division, Fourth Department, thought that a 911 caller who identifies himself, provides information as to his location, and gives a telephone number, isn't "anonymous" and is presumed to be reliable.
There was a disconnect there.
To view a copy of the Appellate Division's decision, please use this link: People v. Hillard