Ducle, then 5 years old, was last seen playing with her younger brother at Bridgeton City Park in Cumberland County on the afternoon of September 16, 2019.
Since she disappeared, investigators have released several age-progression photos showing what Dulce might look like.
The most recent was released in 2023.
So far in 2024, investigators with the county prosecutor's office and Bridgeton police say they have followed up on 17 new tips. Some of those new tips came from outside New Jersey, including tips from Pennsylvania, Massachusetts, New Hampshire and Nevada.
"Unfortunately, those leads did not result in our locating Dulce or the person responsible for her disappearance but it is not for a lack of effort of those dedicated to the investigation," Prosecutor Jennifer Webb-McRae and Bridgeton Police Chief Michael Gaimari said in a joint statement.
About one month after she disappeared, authorities released a sketch of a man who remains a person of interest.
The man was reported to be a Hispanic male, approximately 5'7", slender build, age 30-35 years. He was described as wearing a white T-shirt, blue jeans and a white baseball style hat.
On the day she disappeared, Dulce and her brother had gone off to play on the swings at the park's playground.
Dulce's mother, Noema Alavez Pérez, and her younger sister stayed inside her vehicle while the children played. She would later find her younger son crying, and Dulce was nowhere to be seen.
Anyone with information is asked to contact the Cumberland County Prosecutor's Office through this form at CCPO.TIPS.
Mother of Dulce Maria Alavez expresses regret, defies critics one year after child vanished
----------
* Get Eyewitness News Delivered
* More New Jersey news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube