Police will not release the name of the “person of interest” in the murder of 16-year-old Jholie Moussa, because the person is 17 years old.

Sources told WUSA9 the 17-year-old is Jholie's ex-boyfriend. Jholie’s mom, Syreeta Steward, said she told police about the ex-boyfriend when they first started investigating.

"The reason it was all brought up was because they said she was not in any imminent danger," she said.

RELATED: 17-year-old 'person of interest' charged with assault in Jholie Moussa's case

In a press conference on Tuesday, police said the person of interest has been identified as a 17-year-old male. He was arrested on Jan. 18 and charged with a prior felony assault.

Police said the assault happened before Jholie disappeared. It all came up during the investigation. They would not say why they believe he is person of interest in the murder.

Jholie was last seen on Jan. 12. She told her twin sister that she would be right back, but never returned. Her family reported her missing the next day.

RELATED: A timeline of the Jholie Moussa case

The 16-year-old was labeled as a runaway because she left her home voluntarily. Police say they were working off the information that was provided to them.

Police say by the 16th, they received more information that led them to believe Jholie was in danger and they upgraded her case to "endangered." The next day, the FBI got involved.

WUSA9 asked police why an Amber Alert wasn't issued. Police said there are certain thresholds a case must meet before one can be issued, and that one of the requirements is that there is an abduction.

The autopsy isn't back yet. Police said they don't have a timeframe for it.