Scott Warren, on trial for providing humanitarian aid to two migrants, testified in his own defense on Thursday.

Warren, a volunteer with the advocacy group No More Deaths, faces a possible 20-year prison sentence for two counts of harboring undocumented immigrants and one count of conspiracy to transport and harbor them. He argues that his alleged crimes amount to nothing more than basic human kindness.

On January 14, 2018, by Warren's account, two Central American migrants—Kristian Perez-Villanueva and Jose Arnaldo Sacaria-Goday—arrived unexpectedly at "the Barn," a building in Ajo, Arizona, used by No More Deaths and other aid groups. Upon speaking with the migrants, who were suffering from blisters, dehydration, and exhaustion, Warren performed a brief medical assessment. He says he subsequently arranged a check-up by a doctor, who advised that the two migrants stay off their feet.

Warren allowed the men to remain in the Barn for the next three days. Asked in court whether he intended to break the law, he replied that his "intent was to provide them with some basic humanitarian aid."

Nate Walters, the assistant U.S. attorney, paints a very different picture. He argued in his opening statement last week that the case "is not about humanitarian aid," and that Warren in fact hatched a nefarious plot "to shield illegal aliens from law enforcement for several days."

A great deal of the federal government's case hinges on two pieces of circumstantial evidence, including Warren's relationship with Irineo Mujica, a Mexican-American activist who runs a shelter for migrants in the nearby town of Sonoyta, Sonora. Warren and Mujica met at the shelter several days before Mujica drove both migrants to the Barn, which the prosecution says is proof that Warren planned their stay. In doing so, they say, he conspired against law enforcement.

Warren told jurors that his communication with Mujica actually involved efforts to recover border crossers' human remains from the desert—an activity that No More Deaths and similar volunteer groups often undertake. Mujica has not been charged in the case.

Prosecutors have also highlighted testimony from Border Patrol agents who say they observed Warren pointing to mountains in a conversation with the two migrants. They assumed the exchange included instructions on how to avoid a Border Patrol checkpoint as the men resumed their hike.

According to Warren, he was merely warning the two that it would be "critical" that, in case of emergencies, they keep tabs on State Route 85—the only paved road in the area, which runs between two mountains.

Warren disputes the overall notion that he plotted to shield the men from Border Patrol. "We are not going to hide them, we're not going to keep them from Border Patrol," he says he told the two migrants.

This isn't the only time the crackdown on undocumented immigrants has expanded to become a crackdown on people offering humanitarian assistance. Most recently, a city attorney was arrested and detained for stopping on a West Texas highway to assist three young migrants, one of whom was gravely ill.

Closing arguments in the Warren case are underway this afternoon.