New data suggest a federal program meant to prioritize the deportation of immigrants who have been charged with serious crimes has had only modest impacts on the number of people being detained by the U.S. Immigration and Customs Enforcement (ICE).

What’s known as the Priority Enforcement Program was launched by the department of Homeland Security in 2014.

According to data collected by TRAC, a federal records database at Syracuse University, about 57 percent of ICE issued detainment requests were for immigrants who had been convicted of a crime the year before the program was implemented. In 2015, that fell to just 49 percent.

"The bottom line is that the promise has not been fulfilled, despite the fact that ICE data indicate that local law enforcement agencies are cooperating," said Sue Long, TRAC's co-director.

Looking deeper, the report shows, of those immigrants convicted of a crime, only a quarter had a “serious” offense on their record.