Updated

A federal agent who was killed after shooting his supervisor in a workplace confrontation in California had been the subject of complaints by immigrant advocates for allegedly using coercive tactics with immigrants after a 2010 raid, according to court papers filed on Thursday.

In an amended complaint, the American Civil Liberties Union of Southern California asked a federal court in Los Angeles to order Immigration and Customs Enforcement to turn over records related to a worksite raid overseen by agent Ezequiel Garcia.

An ACLU attorney had complained more than a year ago that Garcia arrested a worker for failing to disclose her immigration status in an interview with investigators following the raid at Orange County's Terra Universal Inc. Garcia also arrested another worker months later on what may have been a retaliatory tip from his recent employer, the court papers alleged.

The ACLU said the recent workplace violence at ICE's Long Beach office involving Garcia underscored the need to get more information about the Terra raid.

"It will further contribute to the public's understanding of whether ICE took disciplinary or supervisory action upon receiving complaints about Mr. Garcia's conduct or other unlawful or abusive conduct in connection with the Terra worksite raid," the ACLU said in papers filed on Thursday.

Garcia, who was promoted to supervisor in 2004, was being counseled on his job performance on Feb. 16 when he shot and wounded Kevin Kozak, ICE Homeland Security Investigations' second-in-command for the Los Angeles area. Another agent pulled out his gun and shot and killed Garcia.

ICE spokeswoman Virginia Kice declined to comment on the shooting, citing the pending investigation.

A federal official with knowledge of the investigation previously told The Associated Press that Kozak had denied a request for an internal transfer request by Garcia. The official spoke on condition of anonymity because he was not authorized to discuss the investigation publicly.

Garcia joined INS in 1988. Shortly after the Department of Homeland Security was created in 2003, he was promoted to supervisor for a documents and benefits fraud task force.

According to the ACLU, Garcia was the lead agent in charge of the raid at the Fullerton, Calif.-based manufacturer where immigration agents arrested 43 workers.

A week later, Garcia interviewed several workers at ICE's offices in Santa Ana, including one who remained silent during questioning. In turn, Garcia arrested her and she spent a day and a half in immigration detention, the ACLU alleged in court papers.

Afterward, ACLU attorney Jennie Pasquarella wrote a letter to ICE director John Morton complaining about Garcia's behavior. An official wrote back indicating the agency would not seek to deport the woman, Pasquarella said.

The ACLU sued Terra in 2010, accusing the company of bilking immigrant workers out of pay and violating their rights. After filing, Garcia went to the house of one of the named plaintiffs and arrested him, noting he had been tipped off by a Terra manager that the man had not previously been detained, the court papers allege.

In a statement in 2010, Kice said that the worker arrested after the raid had been identified through the government's investigation of Terra as a suspected illegal immigrant but he fled the premises during the raid. She also said the government's priority was to focus on the conduct of Terra.

The Department of Labor also filed a suit against Terra and settled last year, winning nearly $374,000 in back wages for the workers.

Earlier this week, Terra's owner George Sadaghiani agreed to plead guilty to a misdemeanor count of hiring illegal immigrants in papers filed in federal court.

Some of the workers arrested in the raid face deportation proceedings.

Last year, the ACLU filed a lawsuit after the government denied its application for a fee waiver to obtain records related to the Terra raid and assessed more than $10,000 in search fees.