TUCSON, Ariz. (AP/FOX 10) -- A federal jury couldn't reach a verdict against a border activist charged with conspiracy to transport and harbor migrants in a trial that has drawn attention to humanitarian workers who help people in the U.S. illegally.

Jurors said Tuesday that they were deadlocked in Scott Warren's trial. He faced up to 20 years in prison.

Defense attorneys argued that the 36-year-old college geography instructor was fulfilling his role as a humanitarian by providing two migrants with water, food and lodging when he was arrested in early 2018.

Prosecutors assert that the men weren't in distress and that Warren conspired to transport and harbor them at a property used for giving aid to newly arrived migrants in an Arizona town near the U.S.-Mexico border.

The humanitarian group No More Deaths has issued a brief statement on the trial, on its unverified Twitter account Tuesday afternoon.

The Associated Press (AP) contributed to this report.