By MATTHEW JAFFE

CHICAGO - An off-duty Chicago police officer shot and killed a man late Saturday night after a deadly confrontation ensued when the cop struck the man's daughter with his motorcycle.

The officer was heading home Saturday through the town of Maywood when his bike hit 4-year old Taniyah Middleton. When the girl's father Christopher, 26, confronted the officer over the incident, the officer shot and killed him.

Friends of the late father remembered him Sunday as a "helpful" and "happy" man.

"Chris was a great father," Middleton's cousin Mathis Hoskin told ABC's Chicago affiliate WLS. "He was always helpful, never mad - always happy with a smile on his face."

But the events that transpired Saturday night are unclear. Pat Camden, a spokesman for the Fraternal Order of Police, paints a very different picture of the incident than Middleton's friends.

The 43-year old officer, an eight-year veteran of the force, was driving back from work when the girl suddenly sprinted into the street, Camden said.

"He was on his way home and a 4-year-old ran out into traffic," said Camden. "He had a choice of hitting her head-on or dumping his bike and taking the personal injury to avoid hitting the 4-year old - which he did. But as he dumped the bike, it slid across the road. She wound up getting nicked by the bike. He wound up with a broken ankle, a dislocated shoulder."

"After the accident he gets up and the girl's father became irate with him and comes over to him," Camden continued. "The officer tells him, 'I'm the police. Take it easy.' The guy says, 'I don't give a [bleep] who you are' and hits him in the face. Another man hits him from behind. The officer goes to the ground. They're beating him and he's about to lose consciousness. He pulls his weapon to defend himself at that point, fires one shot, and kills one of the individuals who happens to be the father of the 4-year-old."

"Had the father simply stood there instead of attacking a police officer he might be alive today," Camden stated.

Middleton's relatives said it was understandable that the girl's father was distressed by the incident.

"Of course a father would be upset at the initial reaction of seeing the child in this condition and he confronted the guy and they got into a confrontation," Middleton's uncle Darrell Davis told WLS.

But they claim the officer never identified himself as a cop before firing at Middleton.

"He never let anyone know he was a police officer until after he shot him," witness Cordell Haggard said to WLS.

Both the girl and the officer were transported to Loyola University Medical Center. The girl, Camden said, had "bruises and abrasions." The second man who confronted Middleton, according to Camden, was taken into custody by Maywood Police.

Chicago Police said the incident is under investigation by the Independent Police Review Authority. Larry Merritt, a spokesman for the Independent Police Review Authority, told ABC News they are now "canvassing the area and getting interviews."

"We were notified of a shooting involving an off-duty police officer in Maywood at approximately 10:30 p.m.," Merritt said. "We are now investigating it."