The police chase that took a police helicopter out of control ended when an officer shot a teenager in the leg.
The police officer was not injured.
He said he thought he was doing what was necessary.
The chase began around 5:20 p.m.
Sunday when police were called to a call about a fight inside a home in the 1100 block of North Madison Avenue.
The officer, who was not identified, said he approached the home and a fight broke out.
Police said he opened fire when the teenager pointed a knife at him.
The teenager was taken to an area hospital and is expected to survive.