WASHINGTON (AP) — In a case stemming from the opioid addiction crisis, the Supreme Court on Tuesday appeared ready to side with two imprisoned doctors who wrote thousands of prescriptions for pain medication in short periods.

The justices signaled they would rule that the doctors' trials were unfair because they were prevented from mounting a "good faith" defense that they did not intend any harm to patients.

Justice Brett Kavanaugh said that prosecutors must prove that doctors knew they were illegally prescribing powerful pain drugs in violation of the federal Controlled Substances Act because the stakes are so high.

Juries sometimes make close calls in criminal cases, Kavanaugh said, and if a doctor is on the losing end of a close call, "you go to prison for 20 years."

The court is weighing appeals from Xiulu Ruan of Mobile, Alabama, and Shakeel Kahn, who practiced medicine in Ft. Mohave, Arizona, and Casper, Wyoming.

Ruan is serving a 21-year federal prison term. Kahn is in prison for up to 25 years. A favorable ruling could lead to new trials or the dismissals of charges against them.

The case comes to the court amid record numbers of drug overdose deaths, many from the highly lethal opioid fentanyl. Members of both parties in Congress also are calling for a nimble, new national plan to reduce overdose deaths that include reducing the supply of illicit drugs and increasing treatment for addiction.

As is often true of Supreme Court cases, which focus on legal principles rather than the facts, the justices were less interested in the details of the doctors' actions than they were in the fairness of the criminal cases against them.

Ruan and a partner, James Couch, were convicted of overprescribing medications at their Physicians Pain Specialists of Alabama clinic and a pharmacy.

The two doctors wrote 66,892 prescriptions in 2014, investigators said. They grossed $20 million between 2012 and a raid in 2015, prosecutors said.

Kahn was convicted of conspiracy to unlawfully distribute and dispense controlled substances resulting in death, including oxycodone, an opioid pain reliever, and fentanyl, a synthetic opioid.

Jessica Burch, of Lake Havasu City, Arizona, was a patient of Kahn's who died from an overdose in 2015.

He wrote nearly 15,000 prescriptions for controlled substances between 2011 and the end of 2016, totaling nearly 2.2 million pills and of which nearly half were oxycodone, prosecutors said.

Justice Samuel Alito, a former federal prosecutor, appeared to be the only member of the court who was clearly on the government's side.

Justice Department lawyer Eric Feigin said the court shouldn't buy the doctors' arguments.

"They want to be free of any obligation even to undertake any minimal effort to act like doctors when they prescribe dangerous, highly addictive, and, in one case, lethal dosages of drugs to trusting and vulnerable patients," Feigin said.

Lawrence Robbins, representing Ruan, said the law should give doctors and their patients enough room to "make the best choices for the individual care of what is often invisible and yet real and intractable pain."

A decision is expected by late June.