After 65 years, the Philadelphia Police Department has finally identified “America’s Unknown Child,” commonly referred to as the “Boy in the Box.”

On Thursday, Police Commissioner Danielle Outlaw revealed the boy’s name as Joseph Augustus Zarelli, who was born Jan. 13, 1953, and died in 1957, WPHL reports.

According to the Philadelphia Public Affairs Office, “on February 25, 1957, the body of a young boy was discovered in a box in a wood area of Susquehanna Road in Northeast Philadelphia.

Despite numerous attempts to identify the child throughout the years, the identity of the boy remained a mystery. Through detective work and DNA analysis, police are finally able to identify the child.”

The city’s oldest unsolved homicide has “haunted this community, the Philadelphia police department, our nation, and the world,” Outlaw said at a news conference.

“When people think about the boy in the box, a profound sadness is felt, not just because a child was murdered, but because his entire identity and his rightful claim to own his existence was taken away,” she said.

Police said both of Joseph’s parents are dead, but he has living relatives.

An order signed by a court of common pleas judge to obtain birth records, death records and adoption records for all children born to the established birth mother revealed Joseph has multiple living siblings on both the mother’s and father’s side.

In 1957, police officer Elmer Palmer was called to Susquehanna Road in Philadelphia’s Fox Chase neighborhood, where someone found a naked, badly bruised boy wrapped in a blanket and placed inside a large cardboard box.

Police say he was malnourished and had been beaten to death.

The boy was taken to the Philadelphia Medical Examiner’s Office, where he was determined to be about 4 to 6 years old. He had blue eyes, brown hair that was “crudely cut” close to the scalp, badly trimmed fingernails and measured to be 40 ½ inches tall and weighed only 30 pounds.

(Philadelphia Police Department)

Bruises were visible on the child’s body, and an autopsy revealed the child sustained “multiple abrasions, contusions, a subdural hemorrhage, and plural effusions,” said Captain Jason Smith.

Investigators made posters displaying the child’s face and posted them at grocery stores and on lamp posts and knocked on neighbors’ doors trying to figure out the boy’s identity.

The flier included such details as light- to medium-brown hair, a full set of baby teeth, tonsils, no broken bones, clothing size 4 and shoe size 8D.

Over the past six decades, detectives pursued and discarded thousands of leads.

The case was heard around the world, but no significant updates were ever made until now, thanks to a boom in technology.

Dr. Colleen Fitzpatrick, a forensic scientist and genealogist, said this case took 2 1/2 years to map the DNA and has been the most difficult case of her career.

(AP Photo/Matt Rourke)

The boy had originally been buried in a pauper’s grave, but on Oct. 30, 1998, a court order was obtained to have the child’s remains exhumed and Joseph was given a proper burial at Ivy Hill Cemetery. In 2015, a charcoal-gray headstone was engraved with the words “America’s Unknown Child” and depicted an image of a little lamb.

The Philadelphia Police Department said that although the identity of Joseph has been revealed, a homicide investigation is still ongoing.

Authorities urge anyone with information pertaining to this incident to call 215-686-TIPS. The Philadelphia Police Department is offering a $20,000 reward for information that leads to an arrest.

The Associated Press contributed to this report.