Crossing the border illegally is a misdemeanor. A misdemeanor that is usually waved for people seeking asylum status.

http://dailycaller.com/2018/06/18/illegals-other-children-asylum-claims/

http://www.breitbart.com/big-government/2018/06/19/exclusive-jim-jordan-ryan-amnesty-bill-not-consistent-with-2016-election-mandate/

“We had ICE in our office last week, and they told us just on the asylum issue, just on asylum, 2,000 people a week showing up at the border,” Rep. Jordan said. “Think about that, that’s 100,000 people a year and they told us that 80 percent of those people wind up not being legitimate asylum seekers.”

And they can't just treat this like a regular misdemeanor. If you let them go they are then in our country illegally and they will not show up for any court date. This is not jaywalking.