San Francisco leaders have approved legislation that would make it harder to deport illegal immigrants who have been arrested and are in police custody.

The Board of Supervisors voted Tuesday in support of a measure that limits conditions under which law enforcement officers would be allowed to contact Immigration and Customs Enforcement to report an illegal immigrant in custody.

The new conditions maintain the alien must have been convicted of a violent crime in the past seven years.

San Francisco is one of 300 sanctuary cities throughout the U.S. City ordinances do not require police to adhere to hold illegal aliens for 48 hours after being released until regional immigration officials can take them into federal custody.

The change to Bay City policy comes 11 months after Kate Steinle's death last July. A five-time deported Mexican man accidentally shot Steinle with a federal agent's gun. The incident triggered a national debate about the presence of 11 million illegal immigrants in the U.S., including those who have also broken criminal laws.