NORMAN, Oklahoma - The nation’s first state trial against drugmakers blamed for contributing to the opioid crisis started Tuesday in Oklahoma in a case that could shape negotiations to resolve the roughly 1,500 other opioid lawsuits consolidated before a federal judge.

Oklahoma Attorney General Mike Hunter started opening statements by saying powerful painkillers have led to the “worst manmade public health crisis” in U.S. history. The state alleges drugmakers extensively marketed highly addictive opioids for years in a way that overstated their effectiveness and underplayed the risk of addiction.

“This crisis is devastating Oklahoma,” Hunter said, adding that opioid overdoses killed 4,653 people in the state from 2007 to 2017.

Drugmakers deny Oklahoma’s claims. The companies maintain that they are part of a lawful and heavily regulated industry that is subject to strict federal oversight, and that doctors are the ones who prescribe the drugs. Much of the opioid crisis, they argue, is the result of illegal activity, such as drugs being stolen or obtained fraudulently.

Lawyers for consumer products giant Johnson & Johnson and several subsidiaries, also delivered opening statements Tuesday.

Janssen Pharmaceutical Cos. attorney Larry Ottaway said the Johnson & Johnson subsidiary represents only a small part of a vast supply and distribution chain for opioid products that is extensively regulated by various federal agencies, including the U.S. Food and Drug Administration. He said the company’s fentanyl patch Duragesic represented only a tiny fraction of the opioid market in Oklahoma and was not widely abused or sold on the street like other drugs.

“It has low rates of addiction and low rates of diversion,” Ottaway said of the Duragesic patches. “When you hear about pill mills, you don’t hear about patches.”

Two other companies, OxyContin-maker Purdue Pharma and Teva Pharmaceuticals , have already settled with Oklahoma.

The trial could bring to light documents and testimony that show what the companies knew, when they knew it and how they responded.

A federal judge in Ohio is overseeing the 1,500 consolidated opioid lawsuits filed by state, local and tribal governments.

Cleveland County District Judge Thad Balkman, not a jury, will decide the case. He is allowing cameras in the courtroom, which is a rarity in Oklahoma.