The New York Police Department has made an arrest in the case of "Baby Hope" after a tip lead to identifying 4-year-old Anjelica Castillo 22 years after he death.

Anjelica was found in a cooler near the Henry Hudson Parkway in New York City on July 23, 1991.  The NYPD officials investigating the case were not able to identify the girl at the time, but paid for her funeral, including a white dress she wore as she was laid to rest.

"Over the years, the optimism was always there except the frustration would grow," Detective Joseph Reznick, now a New York Police Department assistant chief who, in 1993, read the eulogy at the girl's burial, told the Associated Press.

"You know the expression 'I'm on cloud 9?' Well, that's where I am right now," former detective Jerry Giorgio told AP.  Giorgio investigated the case from 1991 until this summer, as he retired from the Manhattan district attorney's cold case squad.

In July, NYPD officials urged the public for their help once again, asking for them to come forward with any information they may know of relating to the case.  A tip reportedly from Anjelica's aunt lead to DNA identification of "Baby Hope." 

The tip also led investigators to Conrado Juarez, 52, who was arrested for sexually assaulting and murdering Anjelica more than 20 years ago.

According to the Associated Press, Juarez confessed to the murder after police interrogation on Saturday.  Juarez is was the cousin of Angelica's biological father.

"He said he took Anjelica into an empty bedroom at a family apartment and sexually assaulted her, then suffocated her with a pillow, police said. He and his sister, who has since died, folded up the body, bound it, wrapped it in cloth and put it inside the cooler, then told relatives they were headed to the beach," Reznick said.

However, Juarez's lawyer is questioning whether the confession should be admitted because of the circumstances of the questioning.  Juarez was interrogated for 12 hours before confessing to the alleged crime.

NYPD officials have added Anjelica's name to her grave.