The following UPDATE was issued by Phoenix Police:

SCOTTSDALE - Driver of motorcycle: W/M 21 years old, transported to hospital and died at the hospital. 

Motorcyclist killed in Scottsdale wreck

azfamily.com

VIDEO: Deadly wreck
RAW: One dead, one critical after accident
PHOTOS: Crash scene

Driver of blue Acura: W/M 65 years old, transported to hospital with non-life threatening injuries. 

On 5-21-08 at about 11:00am an officer attempted to pull over a motorcycle that was weaving in and out of traffic while southbound on Tatum Blvd. When the officer initiated the traffic stop just north of Kings on Tatum the driver of the motorcycle accelerated quickly while southbound and hit a blue Acura that was turning left from Kings to go northbound on Tatum. Both vehicles had very extensive damage. The driver of the motorcycle was transported to the hospital but died at about 11:45am. The driver of the Acura was also transported to the hospital with non-life threatening injuries. 

At this time we do not have an estimate on the speed of the motorcycle at the time of the collision. That will be part of the investigation. The driver of the blue Acura was not cited and based on witness statements the speed of the motorcycle was a main factor in this collision.

ORIGINAL REPORT:

SCOTTSDALE -- Police are investigating a fatal accident at Tatum Road and King Road involving a motorcycle and a car.

According to reports from the scene, a motorcyclist was weaving in and out of traffic in the area. Police were following the motorcycle but were not engaged in pursuit. The motorcyclist collided with a left turning Honda Acura at the intersection of Tatum and King. The rider died in the collision.