Kristen Bialik, Pew Research Center, February 15, 2018

Immigrants with past criminal convictions accounted for 74% of all arrests made by U.S. Immigration and Customs Enforcement (ICE) agents in fiscal 2017, according to data from the agency. The remainder were classified as “non-criminal” arrestees, including 16% with pending criminal charges and 11% with no known criminal convictions or charges.

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Overall, the number of ICE arrests decreased sharply during that span, from 297,898 in 2009 (the year President Barack Obama came into office) to 143,470 in 2017 (when President Donald Trump took office). However, last year’s total represented a 30% increase from the year before, with most of the increase coming after Trump signed an executive order to step up enforcement.

While ICE arrests overall rose from 2016 to 2017, arrests for those without prior convictions drove the increase. The number of arrestees without known convictions increased 146% (up more than 22,000 arrests), compared with a 12% rise among those with past criminal convictions (up nearly 11,000). Still, the bulk of those arrested in 2016 and 2017 had prior convictions.

ICE arrests can happen in a variety of ways. The agency relies on government databases to help track fugitives, and it can detain suspects in courthouses. But in most cases, ICE takes custody of people after local or state police have arrested them.

Among ICE in 2017 with prior convictions, the most common criminal conviction category was driving under the influence of alcohol (59,985 convictions, or 16% of the total), followed by possessing or selling “dangerous drugs” such as opioids (57,438, or 15%). Immigration offenses, which include illegal entry or false claim to U.S. citizenship, were the third-most common crime type (52,128 convictions, or 14{snip}

For ICE arrestees with pending criminal charges in 2017, general traffic offenses topped the list of most common charges (24,438, or 17% of all charges), followed by driving under the influence of alcohol (20,562, or 14%) and possession or selling of “dangerous drugs” (19,065, or 13%). Pending immigration violations were the fifth-most common charge (10,389, or 7%).

Assault ranked among the five most common pending criminal charges and conviction categories for ICE arrestees in 2017, accounting for 11% and 8% respectively. {snip}

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