The woman says it happened at around 11:50 a.m. inside the park at 72nd Street on the Upper West Side.
NYPD detectives used flashlights as their search for evidence continued into the night.
The brazen midday assault and rape all but shut down that section of the park.
Across the city, the search is on for the man in the photograph released by police.
It was captured by a surveillance camera. In it, the man is seen walking down a city street.
Late Wednesday, police also released a surveillance video of the man wanted for questioning.
The attack happened shortly before noon in an area of Strawberry Fields that according to police is, "off the beaten path."
Police say the woman was in the park bird watching.
"He was doing some act, may have been exposing himself or something along those lines. She, we believe, may have taken a picture of him and he then sexually assaulted her," Police Commissioner Ray Kelly said.
Eric Ozawa, a college professor, found the woman in the bushes.
"She told me she had been raped and beaten and someone had taken her bag," Ozawa said.
That bag, law enforcement sources say, is the backpack the man in the picture has on him, and in his left hand.
Investigators believe he may speak with a Russian accent.
So far, Eyewitness News is told that police don't know who he is or where he was headed.
In the park, across from the Dakota, home to the rich and famous, a crime scene is what's drawing people's attention right now.
In a place, most people say, they usually feel safe.
"Never take for granted your safety and always be aware," said Michael Gonzalez, an area resident.
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