U.S. Attorney for Oregon Billy Williams appeared on Oregon Public Broadcasting this afternoon to defend his office's decision to prosecute a Native American teenager for allegedly possessing a gram of cannabis.

Last month, WW reported that 19-year-old Devontre Thomas faced a year in prison for allegedly trying to buy a gram of weed at Chemawa Indian School in Salem.

The case sparked global outcry—including denunciations from the Oregon congressional delegation—and Williams' office agreed two weeks ago to drop the charges.

Williams declined to comment to WW after agreeing to drop the charges Aug. 4—but today made a radio appearance to defend the his prosecutors' choices.

Williams said his office never intended to send Thomas to jail—but wanted to enforce the rules against drug use at Chemawa, a federally-run boarding school.

"He's not 18," Williams said. "That's the first starting point. There's a zero-tolerance policy at Chemawa for any drug activity, whether it's personal use or trafficking."

Williams told OPB's Think Out Loud that his office was aware of how unjust the case might appear.

"That's part of the decision-making process that every lawyer in our office goes through," he said. "They're mindful of the power of the federal government. We instill that in our lawyers. We're mindful of the national discussion going on about marijuana. But we're also mindful of our responsibility to this school."

But he defended the decision of his prosecutors to push the case—in what he implied was an effort to scare Thomas straight.

"I have a lawyer who was doing her best at assessing what would be appropriate and how do we put Mr. Thomas in the best position to successfully avoid a prosecution," he told OPB.