The jury selection and trial against Glenn Chin began this week. 

Chin was the supervising pharmacist at the New England Compounding Center (NECC) five years ago, and now he’s facing charges of second-degree murder.

It all goes back to the fall of 2012, when hundreds of people in 20 different states fell gravely ill from an infection that’s rarely seen: fungal meningitis.

The outbreak was traced back to vials of contaminated medication made at the compounding pharmacy in Framingham where Chin worked. Investigators found mold in some of the pharmacy's supposedly sterile steroid injections.

“Because those steroids were sent through the mail out of state, it became a federal crime,” said Daniel Medwed, WGBH News legal analyst and Northeastern University professor. “The two biggest fish in this enterprise were Barry Cadden and Glenn Chin.”

Barry Cadden was the co-owner and president of NECC and Glenn Chin was the supervising pharmacist.

Prosecutors charged both with second-degree murder, mail fraud and racketeering. Both pleaded not-guilty, and both blamed each other for the outbreak.

Cadden went on trial earlier this year. His defense team argued he wasn’t in the lab making decisions, and he acted as soon as he realized something was wrong. They played a voicemail he left for a clinic after he’d heard that there were problems with some medications: “We would like you to quarantine this product at this time and call us as soon as possible to discuss the situation,” Cadden can be heard saying. “We consider this an emergency.”

Prosecutors argued Cadden was greedy and he valued money over patient's lives. He instructed his employees to ignore cleaning procedures, use expired drug ingredients, and skirted industry regulations.

Jurors saw Barry Cadden in a staff training video where he mentioned regulators disparagingly: “They don’t even know what they are looking at. They have no clue. They go around and they’re like: ‘Oh Barry’s place looks great. Hey, I got to go. Cup of coffee.’ And they go out the door. Really, that’s what it’s like," Cadden said. 

Jurors agreed the behavior was criminal.

“Barry Cadden was convicted of a number of crimes, including racketeering and mail fraud and conspiracy,” said Medwed. “He was ultimately sentenced to a little more than nine years in prison.”

However, even though the tainted products led to the deaths of more than 60 people, Cadden was acquitted of second-degree murder – and got a far shorter sentence than prosecutors had wanted. Medwed says that raises the stakes for Glenn Chin’s trial.

“This is the last chance for federal prosecutors to hold somebody accountable for a homicide. So that could mean that prosecutors could be especially aggressive and assertive," he said.

Medwed thinks the case against Chin may be less challenging for prosecutors than the case against Barry Cadden, who oversaw the business side of things.

“Glen Chin might be in greater jeopardy of a conviction on one or more of those murder counts because of his close proximity to the production of the tainted pharmaceuticals," Medwed said.

As the supervising pharmacist, Glenn Chin was in the labs where the medications were made. “Therefore, it will be easier for prosecutors to prove causation,” Medwed added. “His misconduct or his lack of oversight directly caused the fatal result.”

However, during opening statements, Chin’s lawyer argued that the second-degree murder charges are an overreach. They say there was no malice or intent to cause harm and, at worst, Chin is guilty of involuntary manslaughter.

Chin’s defense team blamed Barry Cadden and said that Glenn Chin was an employee facing enormous pressure.

Chin has been under house arrest since late 2014. He was stopped at Logan airport on his way to Hong Kong – he says he and his family were on a round-trip ticket to attend a wedding.