BEXAR COUNTY, Texas -- A group of union workers took over the steps of the Bexar County Courthouse Tuesday morning, fighting for one of their own.

A former Bexar County probation officer says that he was fired after exposing what's considered a "deadly department policy."

Sergio Castilleja exposed probation department protocol allowing wanted criminals to walk out of probation offices instead of being detained. Shortly after Castilleja spoke out late last year, he says that he was given an ultimatum: resign by December 30 or get fired.

"Put it down, Jarvis. Say that you're leaving before you get fired, because we intend to fire him," said Linda Chavez Thompson of the Adult Probation Officer's Union.

Thompson was referring to Jarvis Anderson, the director of the Bexar County Adult Probation Department. Under Anderson's reign, administrators fired both presidents of the Bexar County Probation Officer's Association. One of them was Castilleja, who worked as a probation officer for 21 years.

"This is a problem that the community needs to know, be aware of," Castilleja said. "I get a lot of e-mails and [union members] are not showing up because of retaliation. It's very strong in this department. The retaliation is really strong, the worst that a lot of unions have seen."

Castilleja refused to resign, and was fired January 3.

Attorney David Van Os is the legal counsel for Steel Workers Local that represents employees at the Bexar County Adult Probation Department. He says that the reasons for Castilleja's termination include a mishandling of 14 probation cases from early 2015 to August 2016.

Castilleja claims that he wasn't informed of his poor performance and received nothing but praise from supervisors during that time.

In an administrative hearing over Castilleja's performance, one of his supervisors defended his work.

"That Sergio Castilleja was a good probation officer and that he, as his supervisor, did not agree with the idea of firing Sergio Castilleja," Van Os said. "The allegations of misperformance Director Anderson leveled against Sergio are nothing but a false, phony pretext for retaliation."

Castilleja helped start a petition, signed by over 100 employees, expressing a vote of no confidence in Director Anderson in 2014. The petition mentioned the department's policy allowing wanted criminals to walk out of probation offices.

Van Os says that Anderson is appointed by district judges. In a secret meeting before the New Year, the majority voted to keep him.

In the past, the probation department had their own security team that would hold wanted criminals until sheriff's deputies could detain them. Since they branched out into satellite offices, Castilleja says that the lack of manpower caused criminals to walk out the doors.

"Now, a person has passed away because of that and others have been injured by people leaving our office not arrested," Castilleja noted.

John Alvarado's son, 27-year-old John Gabriel Alvarado, died after the car he was in crashed into a tree after a high-speed chase on September 16, 2016.

"My son was a passenger in that vehicle. When they hit a tree, that vehicle split in half," said Alvarado, who pointed out that the driver, 22-year-old James Justice, walked out of the probation office with active warrants.

James Justice now faces murder charges.

"It could have been prevented," Alvarado said. "They could have detained Justice and it wasn't done. I do hold Jarvis Anderson accountable for that."

The union's lawsuit against Jarvis Anderson claims that he violated his written policy prohibiting retaliation against the union. Van Os says that on July 1, 2010, Anderson distributed a written policy to employees, including a quote from Texas law that forbids union retaliation.

"A. The right of a person to work may not be denied or abridged because of membership or non-membership in a labor union or other labor organizations," Van Os read. "B. In the exercise of the right to work, each person shall be free from threats, force, intimidation or coercion."

Officers with the San Antonio Police Department are now helping Bexar County probation officers detain criminals during certain shifts throughout the day.

Tom Cummins, the president of the San Antonio American Federation of Labor and Congress of Industrial Organizations (AFL-CIO) says that they plan to call on all judges to review what is going on at the probation offices and to remove politics from the department.

KENS 5 spoke with Director Anderson over the phone on Tuesday. He said that he isn't able to comment on any personnel issues.