U.S. authorities have charged more than 110 people on federal counts related to the Islamic State terror group since 2013, according to the Justice Department.
Assistant Attorney General John Carlin told reporters Monday that in more than 80 percent of those ISIS-linked cases, a community member reported witnessing the perpetrator engaging in the activity that landed him or her in prison, Reuters reported Monday.
But in more than half of those cases, Carlin said the witnesses did not report suspicious behavior to law enforcement until after the culprit was charged.
He said Americans need to make a greater effort to preemptively alert federal authorities if they witness someone expressing support for terrorist groups, including ISIS.
Many of those prosecuted since 2013 were charged under federal law for providing material support to ISIS.
Last year, the Justice Department arrested 60 people on ISIS-related charges, marking an annual high. The number of individuals arrested this year has so far been lower.
