The shooting happened at 4:30 p.m. around the area of Ocean Boulevard and Elm Avenue, and Long Beach police still had part of the road shut down as of late Sunday night.
Fans attending the Grand Prix at the time of the shooting could hear the gun shots and see the commotion coming from the swarm of police arriving on the scene.
Witnesses recalled the scene to ABC7.
"Coming down Ocean Boulevard and all of a sudden a police officer jumps onto the sidewalk," said Al Castro, a witness. "I yelled, 'Tammy watch out!' This car is coming on the sidewalk. Then we saw, it looked like a guy was cornered or jumped out of a truck or trucks, because then they closed it all down"
A resident of a nearby apartment building had an aerial view of the event as it unfolded, and he shared what he saw with ABC7.
"I heard like a stampede, like a lot of people stampede echo between the buildings and screaming and crying, and everyone saying like run, run run!"
Police say the shooting occurred after an officer responding to an earlier shooting at 3rd and Elm saw the suspect.
"Officer on patrol looking for the initial suspect heard shots. At that time he located the suspect. At which time an officer-involved shooting occurred," said Commander Michael Pennino of the Long Beach Police Department.
The suspect was rushed to the hospital and is recovering from non-life threatening injuries.
A handgun was recovered at the scene.
Police believe the suspect may be responsible for three shooting incidents in the area, including one that left a man wounded.
The identity of the suspect has not been released.
"Very scary, even functions like this, I'm always worried about bombs and shooters and it's really bad," said Tammy Clark, who attended the Grand Prix.
But, with thousands in attendance at the Grand Prix on Sunday, police say security for the event was a top priority.
"We had a lot of resources here to keep people safe, and I believe, with the resources properly deployed, that's what led to the immediate apprehension of the suspect," said Pennino.