HARRIS COUNTY, Texas — A man locked up on sex assault charges, is accused of sexually assaulting a sergeant inside the Harris County Jail.

The attack being described as brutal.

“We had one of our own family members get brutally attacked and sexually assaulted. It’s shaken our agency to the core,” said David Cuevas, President of the Harris County Deputies Organization.

The violent attack happened inside the Harris County Jail at 1200 Baker Street Monday afternoon; crime scene unit and detectives inside for the investigation as the female sergeant remained hospitalized.

“We had one of our employee reps go down to the hospital and he said it’s the worst beating he’s ever seen in his 46 year career,” said Cuevas.

According to the Harris County Sheriff’s Office, it happened around 2 p.m. Sources say the inmate ambushed her inside an office on the fifth floor.

He was unescorted and jailed for two previous sex-related crimes.

Now, 27-year-old Jeremiah Williams faces additional charges.

He was arrested last year on charges he attacked two women separately at a west Harris County park.

In a press release, Sheriff Ed Gonzalez said, “The brutal attack of our sheriff’s office teammate warrants a thorough and swift investigation. Uncovering all the relevant facts related to this alleged assault is a top priority as we seek answers and justice.”

The sergeant’s attack comes a month after 19-year-old Fred Harris, a man with special needs, was beaten to death inside the jail.

A fellow inmate twice his size has been charged with murder.

In September, the Harris County Deputies Organization sued the county alleging unsafe jail conditions and understaffing.

“There’s not enough people in that jail. I keep saying that. I keep warning them and they don’t listen,” said David Batton, General Counsel.

Cuevas says what happened to today’s victim is sending shockwaves of fear through jail staff.

“We have employees who are calling who don’t want to show up to work,” said Cuevas.

The sheriff’s office says in addition to the criminal investigation, an internal review will be done as well.

Written by CNN Newsource / KTRK