During the Obama administration, Immigration and Customs Enforcement was not following proper procedures when checking if illegal aliens were known terrorists, jeopardizing national security, according to an audit.

The office of inspector general found that between 2013 and 2015, ICE was not screening illegal immigrants who had been released for terrorist ties. Every single case of a suspected terrorist reviewed by the inspector general included errors, where ICE officials were not in compliance with security standards.

"ICE Enforcement and Removal Operations (ERO) faces challenges in implementing the Known or Suspected Terrorist Encounter Protocol (KSTEP) screening process, which is used to identify aliens who may be known or suspected terrorists," the inspector general said. "Although ERO uses KSTEP to screen all aliens who are in ICE custody, ERO policy does not require continued screening of the approximately 2.37 million aliens when released and under ICE supervision."

Between 2013 and 2015 there were 142 cases of illegal immigrants who were detained and identified as "known or suspected terrorists." The inspector general reviewed 40 of those cases.

"All 40 files had at least one instance of noncompliance with KSTEP policy, generating greater concerns regarding the population of aliens screened and determined to have no connections to terrorism," the inspector general said.

In addition to not following security protocols, the majority of ICE field offices do not have access to the Department of Homeland Security's classified networks, which enables them to "communicate about derogatory information related to known or suspected terrorists."

"As a result, ERO may be missing opportunities to identify, take into custody, communicate status of, and make decisions on those aliens who pose the highest risk to national security and public safety," the inspector general said.

Of the 40 cases reviewed under the audit, nearly half were missing required background checks while the illegal alien was detained.

"ERO is to conduct separate biographic and biometric queries on every alien taken into custody and/or released," the inspector general said. "However, in these instances, at least one of the required queries was either run by non-ERO personnel, was not performed while the subject was in ICE custody, or was not applied."

In addition, ICE did not always run initial background checks, "contact the appropriate external personnel at the required points in the process," or "fully document its actions."

ICE blamed these deficiencies on "limited program oversight and weak management controls."

In 10 cases, ICE had not completed requirements for "reporting aliens confirmed as known or suspected terrorists," including not placing a hard copy noting the alien's terrorism ties in their case file.

ICE warned that the problem is continuing into the Trump administration, noting the agency has identified "at least 19 more cases since January 2016 when field personnel did not transmit the required incident reports to ICE headquarters."

The inspector general identified at least nine field offices and smaller offices that as recently as July 2017 did not "have the infrastructure necessary to communicate derogatory information about known or suspected terrorists."

"The lack of real-time information sharing capabilities jeopardizes ICE's ability to make decisions on known or suspected terrorists," the inspector general said.

The inspector general also issued a rebuke to sanctuary cities, saying local law enforcement agencies that refuse to cooperate with ICE prevent the government from "screening many other criminal aliens" and identifying "possible terrorist connections."

The audit identified 675 jurisdictions that "declined to honor more than 29,269 ICE immigration detainers from January 2014 through May 2017."

"When a state or local law enforcement agency declines to transfer custody of a removable criminal alien to ICE, the released alien may put the public and ERO personnel at risk and requires significantly more resources to bring the individual into ICE custody," the inspector general said.

ICE agreed with all of the inspector general's recommendations to improve its coordination within its terrorist checking system. The agency vowed to expand terrorist screening and increase the number of senior deportation officers in field offices.

"ICE remains committed to upholding the rule of law and enforcing the immigration laws against those who present a danger to our national security, are a threat to public safety, or who otherwise undermine the integrity of our immigration system," said Stephen A. Roncone, the chief financial officer of ICE.