NEW YORK - Who trained Officer Daniel Pantaleo how to take down a suspect?  He's the officer caught on video in July of 2014 putting Eric Garner in a fatal choke-hold right before he died, a video where Garner said numerous times, "I can't breathe."

There was a hearing inside police headquarters in Lower Manhattan on Thursday about the upcoming departmental trial of Pantaleo. The Civilian Complaint Review Board which is prosecuting the case says the NYPD gave it 33 names of possible police instructors for Pantaleo.

The CCRB is trying to reach them all. The NYPD says it turned over thousands of pages of documents and is trying to help locate instructors who taught Pantaleo in 2006. That's the year he joined the police force.

The NYPD released a written statement after the hearing that said, "The Police Academy did not keep precise records on which instructors specifically trained each individual officer. As a result, a complete list of trainers who definitely instructed PO Pantaleo does not exist."

Garner's family and their supporters are outraged.

Reverend Kevin McCall of the National Action Network said, "Those individuals who trained officer Daniel Pantaleo and they don't know who it is. That's absurd and that is not true. They need to give up the information."

Pantaleo's defense lawyer Stuart London said he knows who taught the officer.

"I have already spoken to him, so that will make it easier for the trial to at least have the instructor who taught him, ‘A’  the use of force and ‘B’ the use of the seat belt method which is what he utilized in this case," London added.

The lawyer argues no choke hold was used. Polcie say they were trying to arrest the 43-year-old Garner for allegedly selling cigarettes illegally on a Staten Island street. The police union says Garner died because of his poor health.

A Staten Island grand jury declined to indict Pantaleo.

Forty to 50 people, including witnesses, police officers and medical experts are expected to testify at the NYPD trial which could result in Pantaleo being fired.

Garner's mother, Gwen Carr, attended the hearing.

"There are other officers also who are involved and they ought to be fired, too," Carr said.

Another possible issue, how the star witness will testify in the trial.  

Ramsey Orta is currently in prison for a crime not related to the Garner case. He recorded the video that has been seen around the world of NYPD officers taking Eric Garner down.

Pantaleo's lawyer, who painted Orta as a bad guy with a criminal history, said,"Mr. Orta will probably be the first witness to testify in this case. The issue with him will be whether he is done by a video conference or whether he will be produced in the courtroom."

Eric Garner's mother said she wants to see Orta testify in person in the police courtroom.

"He's my hero, because without him we would not have been here today. We would not know what actually happened to Eric," Carr said.

The Justice Committee, an activist group supporting Ms. Carr, said it was upset that Daniel Pantaleo was not in the courtroom for the hearing. They believe he is getting preferential treatment.

The next pretrial hearing is in April.    

The case is expected to get started inside Police Headquarters with the first witness on May 13.

Meanwhile, the Department of Justice is still weighing if it will bring federal civil rights charges against any of the officers involved.