Evidence supports claim that people from Middle East are part of the migrant community coming through Mexico

Todd Bensman:

Central American Countries Are Helping Middle Easterners Illegally Enter The United States

Panama and Costa Rica are chokepoints on the migrant trail followed by people from other continents seeking easier U.S. entry through our porous border with Mexico.

Golfito, Costa Rica — It was here in March 2017, at the main aluminum structure of a government migrant camp, that federal Costa Rican police arrested Ibrahim Qoordheen of Somalia as a suspected al Shabaab terrorist operative on his way to the U.S. southern border.

Qoordheen had been smuggled from Zambia to Brazil, passed through Panama, and was making his way north through Costa Rica when the Americans had him arrested here, 20 miles inside Costa Rica, according to an American intelligence official with knowledge of the case who spoke on condition of anonymity. The Golfito camp, with a capacity of 250, was set up as a two-day rest station for South America-exiting migrants whom the governments of Panama and Costa Rica register and help move through northward to Nicaragua.
...
Luckily, the Somali stayed long enough for an American intelligence analyst working with the name he had provided in Panama to unscramble it and match it to a pre-existing intelligence file that identified him as intertwined with an al Shabaab cell and smuggling network in Zambia, the U.S. intelligence official said.

The Americans interviewed Qoordheen at length, but the Somali gave up nothing, the U.S. officer said. The Americans then arranged to have him deported to Zambia, the officer said. It turns out the Qoordheen case was only one of other such episodes about which the American public was never told, where terrorist suspects were discovered migrating through Latin America to the U.S. border.
...

There is more including pictures of the camp transit point.  This guy was not the only terrorist suspect who was caught on his way to the porous US border with Mexico.