(CNN) -- Twenty-two years later, she has a name.
The little girl known only as "Baby Hope," whose abused and decomposed body was found in an ice chest by the side of a New York roadway in 1991, is 4-year-old Anjelica Castillo, New York police announced Saturday.
Police also announced the arrest of the man they say killed Anjelica and dumped her body along the Henry Hudson Parkway. The man, Conrado Juarez, 52, is the girl's cousin. He has been charged with murder.
Detectives from the New York Police Department's Cold Case Apprehension Squad never stopped searching for answers in the case. Each year, on the anniversary of the July 23, 1991, discovery of her body, they would canvass nearby neighborhoods, handing out fliers and asking people for information.
Who was the girl? Who was her family? Who killed her?
It was an anonymous tip called in after the latest canvass in July that helped crack the case, Police Commissioner Ray Kelly said. It led detectives to Anjelica's sister, now an adult; from there, they identified the woman believed to be the girl's mother, he said.
"That individual's actions were the catalyst for this most recent lead," Kelly said, referring to Juarez's arrest. He is Anjelica's cousin on her father's side.
Police arrested Juarez after questioning him near the Manhattan restaurant where he worked as a dishwasher, Kelly said. He was expressionless as police led him in handcuffs past reporters.
Juarez admitted to the crime Saturday morning, Kelly said.
"Today, NYPD investigators have given young Anjelica her due justice," said Chief of Detectives Phil Pulaski.
Construction workers found the body of Anjelica -- who was never reported missing -- bound and in a garbage bag, hidden under some soda cans inside a blue and white cooler. She had been smothered and sexually molested, and her body was so badly decomposed that several sketches were made to suggest what she looked like.
Two years after she was found, the girl was laid to rest in a donated plot, buried in a white dress bought by a detective's wife, with a tombstone paid for by detectives. "Because we care" is the inscription at the bottom of the tombstone, Pulaski said.
Juarez, who was 30 at the time of the crime, said he went to an apartment in Queens shared by seven of his relatives and saw Anjelica in the hallway, Kelly said. Juarez told police he smothered her with a pillow while raping her.
When the girl went motionless, Juarez told police, he summoned his sister from another room. It was the sister who told Juarez to get rid of the body and who provided the cooler, Kelly said. He then "folded the girl in half," tied her, placed her in a garbage bag inside the cooler and placed soda cans on top of her body, said New York Assistant District Attorney Melissa Mourges during Juaraez's arraignment Saturday night.
Juarez and his sister hailed a cab to Manhattan, dropped the cooler off in a wooded area near the parkway, and then went their separate ways, authorities said.
The sister, Balvena Juarez Ramirez, is deceased, Kelly said.
Retired Det. Jerry Giorgio, who worked on the case from the start, said he was "elated" at news of the arrest.
"You know the expression, 'I'm on cloud nine'? Well, that's where I am right now," Giorgio told reporters.
Giorgio told CNN the killer's identity was out of the blue. He said he was certain the killer was Anjelica's mother, father, or both.
Changes in forensic science also helped propel the investigation, Kelly said. The girl's body was exhumed in 2006, and a DNA profile was built in 2011. Earlier this month the office of the chief medical examiner made a DNA match between the girl and her mother.
From there, investigators constructed a family tree, and the trail led them to Juarez, Kelly said.
Kelly praised the "phenomenal persistence" of the detectives who originally worked on the case and those now working with the cold case squad. "They were unrelenting," he said.
CNN's Lorenzo Ferrigno. Susan Candiotti. Erin Duggan. and Margaret Conley contributed to this report.
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