PLATTEKILL, N.Y. (AP) — Investigators are trying to determine why a Hudson Valley motorcyclist took off after a police stop before he died in a crash.

Police say 22-year-old Ryan DiNonno was pronounced dead following Tuesday night's crash in Plattekill.

Authorities say DiNonno was driving without a helmet or license plate in Newburgh when police tried to pull him over. DiNonno kept driving but eventually stopped before taking off again.

Investigators say DiNonno failed to negotiate a turn and crashed into a pole. Police say the chase lasted about five minutes.