Authorities are asking for help in locating a vehicle and two people involved in a homicide last month.

According to a news release from the Scottsdale Police Department, 58-year-old Bryan Blair was riding a bike northbound on Scottsdale Road near McDowell around 6:15 p.m. on February 22 when a man was seen entering the road with a long metal object in his hand.

Police said the man deliberately placed the metal object into the front spokes of Blair's bike as he rode past, causing Blair to be thrown over the handlebars and into the street.

"A subject exited a vehicle and moved into the roadway and threw what appeared to be a steel rod into the front tire," said Scottsdale police spokesman Officer Kevin Watts. "It stopped the bike and launched Mr. Blair into the street."

"We don't know what was in the mind of the person who did it and we don't know what led up to that," Watts said.

The subject was seen getting into the driver's seat of a nearby vehicle that drove away from the scene. Police said there was a second person already in the vehicle, described as a 1995 or 1996 black Nissan 200 SX.

Blair was taken to the hospital with life-threatening injuries. Police said he was hospitalized for several weeks before passing away on March 14.

The driver is described as a white male between 30 and 45 years old with a shaved head. He was wearing a black shirt and brown boots at the time of the February incident, police said. Authorities could not provide a description for the passenger.

Word of the attack has put other cyclists in the area on alert.

"That's pretty downright nasty," said bicyclist Michael Miller. "I don't know why someone would do that. It's definitely scary riding out here on this road, but just stay aware."

Anyone with information about the case is asked to call the Scottsdale Police Department at 480-312-5000 or submit an anonymous tip through Silent Witness by calling 480-WITNESS (948-6377).