Hundreds of convicted criminal immigrants facing deportation have been released back into the U.S. and gone on to commit new crimes. Three Republican senators want to know why they were released in the first place.

Immigration and Customs Enforcement data revealed that from 2010-2014, the Obama administration released 121 convicted criminal immigrants slated for removal who went on to commit murder.

In a letter to ICE head Sarah Saldaña, Senate Judiciary Committee Chairman Chuck Grassley (R-IA), Immigration and the National Interest Subcommittee Chairman Jeff Sessions (R-AL), and Sen. Jeff Flake (R-AZ) point out that the recent revelation is not necessarily a new phenomena.

“This disturbing fact follows ICE’s admission that, of the 36,007 criminals it released from custody in FY 2013, 1,000 have been re-convicted of additional crimes in the short time since their release, including felonies and gang-related offenses,” the three wrote. (Emphasis in original).

“Incredibly, as though releasing these criminal aliens one time is not bad enough, ICE once again released from its custody at least 156 of these repeat offenders back into our neighborhoods, instead of deporting them,” they add.

The three point out that the administration’s failure to contain and deport convicted criminals flies in the face of President Obama’s stated immigration enforcement priority policies.

“This practice is completely contrary to the President’s promise to deport ‘[f]elons, not families . . . .  [c]riminals, not children . . . .  [g]ang members, not a mom who’s working hard to provide for her kids,’” they quote Obama.

Grassley, Sessions, and Flake continue posing a series of questions to ICE focused on the reasons for the criminals’ release, the types of offenses, and locations of the releases.