New York (CNN) -- Twenty-two years after a gruesome and heartbreaking discovery, the New York Police Department continues to search for leads on a cold case.
On July 23, 1991, the body of an unidentified little girl --named "Baby Hope" by detectives -- was found in a blue and white picnic cooler in a wooded area near the Henry Hudson Parkway in New York City.
The girl, believed to be 3 to 5 years old, was smothered and sexually molested. Her body was so badly decomposed that several sketches were made to suggest what she looked like.
Police could not track down anyone who might have known the girl. She was never reported missing.
On Tuesday, the anniversary of the discovery, authorities went to a neighborhood near where the body was found in hopes of finding new leads.
They handed out flyers in the Washington Heights section of Manhattan, "making an amplified request for anyone with information in regards to this incident" to come forward, according to a NYPD press release.
"Several detectives are still on this case," Detective Robert Dewhurst told CNN Tuesday, "we're trying to solicit the public for new information. Maybe someone can provide identification."
People with information may speak many years later for many reasons, such as feeling safer after moving to a new area where they don't see the person responsible every day. Sometimes people "want to get it off their chest," said Dewhurst, who is part of the Cold Case Apprehension Squad.
For months after Baby Hope's body was found, police went back to the site hoping whoever was responsible, driven by guilt, had left some type of memorial that would have helped police.
Two years after she was found murdered, Baby Hope was laid to rest in a donated plot, thanks mainly to detectives who worked on the case. She was buried in a white dress bought by a detective's wife.
Despite the years this case has remained opened, Dewhurst said he is not frustrated.
"This is what my squad does," he said. "Twenty years is not uncommon for a cold case.
"I have hope. Otherwise I wouldn't be doing this."
Anyone with information can call the NYPD tip line at 1-800-577-8477.
CNN's Jeanne Moos and Gary Tuchman, who reported on the Baby Hope case in 1992-1993, contributed to this report.