UPDATED: February , 2018  6:00 PM

AUSTIN, Texas (CBSDFW.COM/AP) —Investigators looking into the Texas youth prison system that has been upended by abuse and misconduct allegations arrested four current and former corrections officers Thursday on charges that include excessive force, theft and document tampering.

A fifth Texas Juvenile Justice Department employee is also wanted but remains at large, the Texas Department of Public Safety said in a statement, bringing the total number of juvenile correction workers facing criminal charges in the past year to at least nine. A 10th former correctional officer was convicted in July on charges of having sex with youth in custody.

The unfolding crisis is the second time Texas’ juvenile corrections agency has been rocked by scandal. Lawmakers overhauled the system in 2007 and shuttered lockups after authorities believed at least 13 boys in custody had been sexually abused.

A spate of new allegations is again raising fears. Among those arrested Thursday was Morsello Hooker, a 31-year-old corrections officer at a rural West Texas lockup. He’s accused in court documents of picking up a 15-year-old who was lying on his back and slamming him on the ground.

The teenager said he was slammed down on his head and another correctional officer told investigators he saw Hooker use “a lot of force,” according to court records. Hooker was released Thursday from Brown County Jail on $5,000 bond. It was not immediately clear if he had an attorney and a phone number listed to him was disconnected.

His arrest comes more than a month after Texas Gov. Greg Abbott ordered the Texas Rangers, the state’s top criminal investigators, to delve into the state juvenile system that holds about 1,400 youth offenders in five lockups across the state.

In recent weeks, Abbott has also replaced the leader of the agency and an independent ombudsman, a position that was created in wake of the Texas juvenile lockup scandal a decade ago.

Governor Abbott released a statement about the arrests on Twitter.

He said, “Misconduct on the part of employees entrusted with the responsibility of protecting our youth will not be tolerated.”

The suspects arrested are:

  • Derrick Goodman, 56, charged with official oppression. Goodman was arrested at the TJJD facility in Gainesville, where he was employed. He was booked into the Cooke County Jail.
  • Shannon Hoaglen, 41, charged with official oppression. Hoaglen was arrested at the TJJD facility in Gainesville, where he was employed. He was booked into the Cooke County Jail.
  • Derrick Day, 39, charged with official oppression. Day formerly worked at the TJJD facility in Gainesville. He was arrested in Gainesville and was booked into the Cooke County Jail.
  • Morsello Hooker, 31, charged with official oppression. Hooker formerly worked at the TJJD facility in Brownwood. He was arrested in Brownwood and was booked into the Brown County Jail.

Texas’ juvenile system today is far smaller than it was at the height of the previous scandal, when the state had more than 5,000 offenders in lockups. But the department has long struggled with turnover and finding qualified correctional officers. Hooker had been on the job a decade before the alleged body slam that led to his arrest, according to agency spokeswoman Carolyn Beck, while the other three arrested Thursday had been on the job for less than three years.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)