California Gov. Jerry Brown signed a bill designed to help undocumented immigrants who are victims of violent crime. The new legislation introduces time limits on law enforcement's response to their U.S. visa applications in an attempt to standardize police forces' uneven treatment of applicants.

The federal government grants visas to undocumented immigrants who help law enforcement try to catch criminals. The so-called U visa allows the recipient to live and work in the United States for four years, but to apply, a victim must first ask local law enforcement to verify their cooperation.

California, the nation's most populous state, becomes the first to mandate that law enforcement sign U visa certifications in a particular time frame.

It requires California law enforcement to verify a victim's cooperation within 90 days, unless the agency can demonstrate that the victim was uncooperative. If the victim is in the process of being deported, the time frame shrinks to 14 days.

A Reuters investigation last year found vast geographic disparities in law enforcement approaches to this visa, with some agencies readily verifying cooperation and others stonewalling.

The report showed, for example, that law enforcement in Oakland, California had verified 2,992 immigrants between January 2009 and May 2014 compared to just 300 in Sacramento, California, which has a slightly higher population.

Congress has limited the number of U visas to 10,000 a year, and the program is heavily oversubscribed. In fiscal 2012, U.S. Citizenship and Immigration Services received 24,768 applications from crime victims certified by local law enforcement.

If the agency determines an immigrant is eligible for the visa but the yearly cap has been reached, that person can still obtain protection against deportation and work authorization while joining the U visa queue.

California legislators unanimously passed the bill this year, and Brown announced on Friday that he had signed it.

Crimes covered by the new law include sexual assault, domestic violence, murder, prostitution, perjury, blackmail, kidnapping, obstruction of justice and fraud in foreign labor contracting, the Los Angeles Times reported.

The bill, created by Senate leader Kevin de León and Speaker of the Assembly Toni G. Atkins, is an attempt to boost immigrant trust in and cooperation with law enforcement. “Every time a criminal goes free because the victim fears deportation and the police, we are all a little less safe,” said de León in a statement.

The measure comes as immigration features heavily in the early stages of the November 2016 presidential election, particularly among Republican candidates, where Donald Trump has made opposition to undocumented immigration a hallmark of his campaign.

Al Jazeera with Reuters