A man waiting for a bus was attacked by a stranger and stabbed for no reason around 7 a.m. Tuesday near Central Avenue and Indian School Road.
Police say the suspect was on a city bus and after getting off at a stop, he stabbed the victim -- leaving a large puddle of blood in the street.
Good Samaritans rendered aid to the man and gave officers a description of the suspect.
The suspect was arrested after a responding officer spotted a person matching the description.
"We have a positive identification on that suspect..unfortunately, neither the suspect nor the victim are talking..so we're trying to piece it together based on what we have out here," said Phoenix Police Sgt. Trent Crump.
"We don't know if these two knew each other," Crump added. "We don't know if there was any prior history or contact between the two..probably won't until our hopefully, our victim is talking."
The victim was transported to an area hospital in extremely critical condition.
No names have been released in this case and a motive for the stabbing is unknown at this time.
This is a developing story. Stay with FOX 10 News for updates.