ARLINGTON -- Wednesday marks 20 years since Amber Hagerman vanished as she rode her bike with her brother in Arlington. The 9-year-old was found dead four days later.

Tuesday morning detectives spoke about the case, saying 3,000 to 8,000 leads have come into their department over the years, but none have led to an arrest. 

No forensic evidence has ever been found, but that doesn't mean the detectives have given up. They say they're working just as hard on the case as they were back then. They're asking the public to think back to 1996 — anything that stands out as strange should be reported to police.

"The killer could be the person next door, the person you go to school with, the person you work with," one detective said.

"Someone knows something," another officer added.

Amber's mom, Donna Norris, also took the podium and tearfully asked for help from the public in bringing justice for her daughter. Norris pushed for the State of Texas to launch the Amber Alert system, which is responsible for saving numerous endangered children across the nation.

"Remember the sacrifice she had to endure, and her killer is still out there," Norris said.

Then, she addressed Amber's killer.

"How could you look in my little girl's tearful eyes and do what you did to her?"