Schmeer was crossing Broadway at West 90th Street when she was hit by two suspects attempting to make a getaway after stealing over-the-counter medication from a CVS drugstore a few blocks away, police and her mother told The Associated Press.
The 39-year-old editor won the award for best editing at last year's Sundance Film Festival for "Sergio," and is also known for her work on many Errol Morris documentaries, including "The Fog of War." She also worked with director Sydney Pollack on "Sketches of Frank Gehry."
"She was just extremely loved by many, many friends," Schmeer's mother told The AP.
Documentarian Morris mourned the editor's death through Twitter.
"An extraordinary editor makes possible something that would not have been possible without them. Karen Schmeer was an extraordinary editor," he tweeted.
And later, "The only thing more appalling than life is death."
Schmeer's colleagues paid their respects at the Sundance Film Festival Awards on Saturday evening.
The driver of the car was arrested on a murder charge shortly after the accident, but police are still looking for two other suspects, police told The AP.
Schmeer was pronounced dead at St. Luke's Hospital.