Federal immigration authorities will give convicts more scrutiny before deciding to release them from custody under new policies the Obama administration announced Wednesday.

U.S. Immigration and Customs Enforcement will now require approval from top officials in ICE field offices before releasing people with convictions for two or more felonies or any single aggravated felony.

ICE will no longer cite a shortage of detention space as the determining factor for releasing people with serious criminal records. The federal agency has also set up a panel of senior managers to review decisions about releasing violent criminals.

Further, ICE is boosting its efforts to supervise those who have been released from custody. And it is working on a way to notify state law enforcement authorities about such releases.

In the fiscal year ending in September, federal immigration authorities released 30,558 people with criminal convictions. That is down 15 percent from the year before, when 36,007 were released.

The majority of the releases during those two years were done in compliance with federal court rulings or bond decisions made by immigration judges, ICE said. The federal agency cited a 2001 U.S. Supreme Court ruling that prohibits ICE from indefinitely detaining people who cannot be deported. ICE is sometimes unable to deport people because their home countries refuse to take them back or delay issuing them travel documents.

“I am determined to do what we can to improve and reform our immigration system within the confines of existing law,” ICE Director Sarah Saldaña said in a prepared statement. “Today’s announcement is an example of this, and I believe it will enhance public safety and public confidence in our enforcement and administration of the immigration laws.”