The victim, 73-year-old Ruth Shack, is in the hospital with several broken bones, including a broken neck.
She was walking in Central Park near 80th Street and West Drive last Saturday when the man on the bike slammed into her.
Her daughter-in-law can't believe someone would so heartlessly leave the scene of an accident as serious as the one that caused Ruth's injuries.
"He stopped long enough to take off his helmet. Said my fault sorry," Lauren Shack said.
The victim's family believes the guy who hit Ruth Shack is part of a group of cyclist who call themselves hammerheads.
That's slang for an aggressive type of cycling.
They are hardcore bikers who ride at high speeds.
On a daily basis, according to some estimates there are 200,000 cyclists on the streets of New York.
And in Central Park, cyclists and pedestrians come together.
Caroline Samponaro is with Transportation Alternatives, a group that tries to educate cyclists about the rules of the road.
"It would never be OK to leave the scene no matter how the accident happens," Samponaro said.
"The fellow that did this needs to come forward," relative Adam Shack said.