Martha and Ronald Wimmer and their lawyer, Ravi Batra, appeared Monday outside Staten Island Supreme Court to discuss the suit they filed Friday.
Monday marks the two-year anniversary of Caroline Wimmer's murder. She was found in her apartment, strangled with her hair dryer.
The suit names several other defendants, including Mark Musarella, the EMT who posted the pictures to Facebook, and his employer, Richmond University Medical Center. The family is also suing Fire Commissioner Salvatore J. Cassano and the Fire Department of New York.
The Wimmers aren't demanding money from Facebook. They want Facebook to delete the picture from its data servers and turn over details about who saw and downloaded it.
"In Caroline's case, pictures were taken without her consent by an EMT that was trespassing when he took his sick and illegal pictures ... Facebook displayed them to its members and allowed them to download the same," Batra said.
But Facebook denied the allegations and refused to comply with the suit's demands.
"We believe this suit is completely without merit and we will fight it vigorously," said Facebook spokesman Andrew Noyes.
The suit seeks unspecified monetary compensation from Richmond University Medical Center and the city.
The city said in a statement it would not comment on the suit because it hadn't been served.
"This is a tragic situation and we extend our sympathy to the family," a spokeswoman for the New York City Law Department said. "We have not yet received the legal papers, but will review them thoroughly upon receipt."
The hospital declined comment.
Musarella was fired from his job and agreed to be stripped of his EMT license and to never again work as an EMT in exchange for no jail time and 200 hours of community service.
Musarella's lawyer, Edward Pavia, said he was unaware of the lawsuit and predicted that his client would not face further legal issues. "Nothing that transpired in the criminal prosecution would expose him to a civil liability," he said.