The number of detainers issued by Immigration and Customs Enforcement (ICE) has dropped 30 percent, from 11,355 in October 2014 to 7,993 in April 2015, according to a report by the Transactional Records Access Clearinghouse (TRAC.)

When a detainer or "immigration hold" is issued, ICE asks local, state and federal law enforcement agencies not to release immigrants at their facilities in order to give ICE an opportunity to take them into custody.

According to TRAC, the decline in the use of detainers parallels a period of growing criticism of the Secure Communities program, which allowed the sharing of information between law enforcement agencies and ICE, and which was abolished last November.

Back then, Secure Communities was replaced by the Priority Enforcement Program (PEP), which restricts detainers to "special circumstances,” including cases in which the individual poses a risk to national security or has been convicted.

However, during April 2015 only 32 percent of individuals on whom detainers were placed had been convicted of a crime and only 19 percent had a felony conviction, while two-thirds had no criminal conviction of any type.