The Sacklers had a new plan.

It was 2014, and the company the family had controlled for two generations, Purdue Pharma, had been hit with years of investigations and lawsuits over its marketing of the highly addictive opioid painkiller OxyContin, at one point pleading guilty to a federal felony and paying more than $600 million in criminal and civil penalties.

But as the country’s addiction crisis worsened, the Sacklers spied another business opportunity. They could increase their profits by selling treatments for the very problem their company had helped to create: addiction to opioids.

Details of the effort, named Project Tango, have come to light in lawsuits filed by the attorneys general of Massachusetts and New York. Together, the cases lay out the extensive involvement of a family that has largely escaped personal legal consequences for Purdue Pharma’s role in an epidemic that has led to hundreds of thousands of overdose deaths in the past two decades.

Image Richard Sackler

The filings cite numerous records, emails and other documents showing that members of the family continued to push aggressively to expand the market for OxyContin and other opioids for years after the company admitted in a 2007 plea deal that it had misrepresented the drug’s addictive qualities and potential for abuse.