State Attorney General Ken Paxton filed a lawsuit against the city of San Antonio last Friday, claiming the city violated state law established by the controversial SB4. The lawsuit follows the actions of San Antonio’s police chief, William McManus, who released 12 allegedly unauthorized immigrants from custody after they were discovered in a tractor trailer last year.

The law, which was called the ‘Sanctuary Cities’ bill during its time in the legislature, compels police departments to cooperate with federal agencies and enables local police officers to check the immigration status of people during routine police work.

The lawsuit argues that, by releasing the 12 individuals, McManus violated the law by failing to cooperate with federal immigration authorities. It also claims that McManus blocked attempts by the Department of Homeland Security to interview the allegedly unauthorized individuals. Lawyers for San Antonio have denied these allegations.

“The attorney general’s characterizations of what happened that day are clearly aimed at furthering a political agenda. The city has a long history of cooperating with federal authorities, and we will continue to do so,” San Antonio City Attorney Andy Segovia said.

SB4 has been hotly debated in Texas communities since its initial introduction in 2017. It was signed by Governor Abbott on May 7 of that year.

Defenders of the law, such as Paxton, assert that it protects Texas citizens and promotes cooperation with the federal government.

“Unfortunately, some municipalities, such as San Antonio, put the safety of police officers and the public at risk by defying state law,” Paxton said when announcing the lawsuit.

Critics of SB4 argue that the law erodes trust between citizens and their local police forces, making it less likely that crimes will be reported and community institutions trusted if individuals are afraid of being asked for their immigration documents.

“Ken Paxton’s dangerous lawsuit will instill fear in immigrant communities and force local law enforcement to choose between keeping their communities safe or aiding Trump’s deportation efforts,” said Manny Garcia, an official of the Texas Democratic Party.

“I think it’s unfair for the state to force police to do the job of the federal government, especially if it reduces the trust communities have for them,” junior Christian Fournier said.

This lawsuit represents the first time Paxton has attempted to enforce SB4. The lawsuit asks the judge of the state District Court of Austin to impose fines totaling over $11 million on the city of San Antonio for the alleged violations, according to the Austin-American Statesman.

The incident that sparked this dispute between the city and the state was part of an investigation into human smuggling, an issue that has befallen San Antonio in the past. In June of this year, the Immigration and Customs Enforcement agency investigated 55 people found in a different tractor-trailer.

Some incidents of human smuggling are not routine cases such as those, however. In July 2017, 10 men were confirmed dead after they were trapped in a tractor-trailer in a Walmart parking lot in San Antonio and suffered from heat stroke and asphyxiation, in what turned about to be another case of the same type. The driver of that vehicle was arrested.