Aug. 31, 2012 -- Five Los Angeles Police Department officers have been placed on administrative duty during criminal and administrative investigations after a woman died in their custody last month, police officials said today.

An "in-car video was reviewed which revealed some questionable tactics and improper comments" during the officers' encounter with the woman, Alesia Thomas, the department said in statement Thursday.

The video has not been made public and the officers have not been named.

"The Los Angeles County District Attorney's Justice System Integrity Division (JSID) and the OIG [Office of the Inspector General] were present at the scene and will conduct a comprehensive and independent review of the facts of the in-custody death," according to the Thursday statement.

Police arrested Thomas, 35, for child endangerment after she left her 3-year-old daughter and 12-year-old son at the Southeast police station at 2 a.m. July 22. The children were stranded with a backpack full of clothes and told police their mom didn't want them anymore, LAPD Commander Andrew Smith told ABC News today.

The children also told police they hadn't eaten anything in a couple of days, Smith said.

Officers contacted Thomas at the children's home and believed they had a legitimate reason to arrest her, according to a police statement released July 23.

Thomas resisted arrest, according to the statement, prompting one officer to perform a leg sweep and take her to the ground to control her. Two other officers handcuffed her, the police statement said.

Officers also restrained Thomas' ankles with a "hobble restraint device," then placed her in a seated position in their patrol car, according to the statement.

At that point, Smith said today, police noticed that Thomas had stopped breathing and pulled her out of the car before contacting paramedics.

Thomas died at the hospital.

Thomas' grandmother, Ada Moses, told ABC News today that her granddaughter was "a beautiful person" and questioned the events of her death.

"Alesia came to see me on that Friday, and that Sunday morning I was getting ready to go to Sunday school and my doorbell rings, and when I went to the door, it was the social worker with her oldest child," Moses said.

The social worker, along with Thomas' son, told Moses that Thomas had died.

Moses said Thomas' children are now in the custody of their grandmother, Sandra Thomas.

Smith said the department is awaiting toxicology reports from the coroner's office to determine whether intoxicants or drugs played a role in Thomas' death.

"I take all in-custody death investigations very seriously," LAPD Chief Charlie Beck said in a statement Thursday. "I am confident we will get to the truth no matter where that leads us."

This investigation coincides with the LAPD's investigation of an Aug. 21 incident in which two officers were caught on camera body slamming a handcuffed nurse to the pavement, then apparently fist bumping afterwards.