California Gov. Jerry Brown on Tuesday signed into law a bill barring grand juries from deciding on charges in cases involving police use of lethal force.

Proponents, including racial equality advocates and police brutality opponents, have argued that grand jury trials are “shrouded in secrecy” and prevent prosecutors from accountability to the public.

State Sen. Holly Mitchell, D-Los Angeles, authored the bill, SB 227, after grand juries in Ferguson, Missouri, and New York City decided not indict police in the killings last year of unarmed black men Michael Brown, 18, and Eric Garner, 43. In both cases, the decisions sparked a public outcry from Black Lives Matter and other activists across the country.

“Criminal grand jury proceedings differ from traditional trials in a variety of ways; they are not adversarial. No judges or defense attorneys participate,” Mitchell said in a statement. “There are no cross-examinations of witnesses, and there are no objections. How prosecutors explain the law to the jurors and what prosecutors say about the evidence are subject to no oversight. And the proceedings are shrouded in secrecy.”

The measure was opposed by law enforcement groups, including the California Association of District Attorneys, which argued that the grand jury system is a useful prosecutorial tool, according to The Los Angeles Times.

When cases like the killings of Brown and Garner arise, prosecutors can choose to convene a preliminary hearing or convene a grand jury to decide on indictment, according to a bill analysis conducted by state Sen. Loni Hancock, D-Berkeley.

In such cases, facing pressure from law enforcement not to file charges and pressure from the community to file, convening a grand jury allows the prosecutor to “pass the buck, using grand jurors as pawns for political cover,” Hancock said.

Another bill signed into law Tuesday, SB 411, reaffirms the right of civilians to record a police officer in a public space.