Polygraph examiners for the Border Patrol are criticized for how they manage examinations in the agency's Tucson sector.
The Border Patrol has traditionally been led by former agents
Five people trying to cross the border illegally have died in the past three weeks in Yuma.
The suit was filed in U.S. District Court in Tucson last week.
Federal agents are investigating a Yuma area shooting.
Part 5: Over the last three years, tens of thousands of unaccompanied minors have fled Central America for the U.S. At least 19 have wound up in the hands of labor traffickers.
Part 4: In the last two years, more than 10,000 child migrants have faced deportation proceedings without ever finding a lawyer to help them. Thousands more children face the same fate despite government efforts to fund more free lawyers.
Part 2: Since the child migrant crisis unfolded two years ago, the United States has assisted Mexico on its southern border. The result has been rising deportations from Mexico amid a rise in allegations of corruption against its immigration agents.
Part 1: Refugees from Central America are pouring into the United States, a trend from 2014 that seems to be growing along the U.S.-Mexico border again this year. Many of them are children, sent here alone.
The May 31 hearing follows a searing contempt ruling U.S. District Judge Murray Snow issued earlier this month, finding the sheriff intentionally violated court orders in a longstanding racial profiling case.