Sergeant Max Fernandez and Detective Mark Lillienfeld were both members of the sheriff department's Civil Rights and Public Corruption Detail, created by Villanueva shortly after he took office in 2018.
The commissioners are trying to determine if Villanueva used the detail to intimidate his political enemies.
"This unit was tainted from the beginning," said Oversight Commissioner Sean Kennedy. "It was selecting officials (who were) asking hard questions... anyone who came in conflict with the sheriff's department."
The commission highlighted the sheriff's department investigation of Los Angeles County Inspector General Max Huntsman, who was heading up a probe into deputy gangs within the sheriff's department.
Commission Chair Robert Bonner calling Villanueva's public announcement of the Huntsman investigation as "inappropriate" and comparing Villanueva's actions to those of past Sen. Joseph McCarthy.
"They're nothing less than McCarthy-esque type tactics," Bonner said. "And we must be sure that this will never happen again."
Villanueva slammed the oversight commission as corrupt.
"This investigation is nothing more than electioneering and lawfare," Villanueva told Eyewitness News.
He says he created the Civil Rights and Public Corruption Detail because of the preponderance of corruption in local government, and claims every case that detail investigated was initiated by a complaint from the public.
"They cannot point to one single case that we initiated on our own or said, 'We're going to go after these people who criticized us,'" said Villanueva. "No. Every one was based on a complaint."
Current Sheriff Robert Luna disbanded the Civil Rights and Public Corruption detail when he took office, but oversight commissioners say the department kept its members, as well as its lack of transparency.
"This is one unit, but there are many other problems in that department, and they continue to hide the department's problems from the oversight commission," said Kennedy. "That's not right."
This was the commission's 10th special hearing on the sheriff's department's public corruption detail and its issue with deputy gangs.
The commission Friday hinted it may subpoena Villanueva to testify again. The former sheriff says he's ready.