Trial 4: The real-life case behind Netflix’s new true-crime series

Sean K Ellis served 22 years in prison after being wrongfully convicted of murder

Trial 4, Netflix’s latest true crime documentary series, has been released.

The eight-episode series, which debuted on the streaming service on Wednesday (11 November), tells the story of Sean K Ellis, an American man who served 22 years in prison after being wrongfully convicted of killing Boston Police detective John Mulligan in 1993.

While evidence suggested that the murder was a hit, Ellis, who had been buying nappies for his girlfriend’s baby at the Walgreens where Mulligan was shot, was deemed to fit the profile of the “usual suspects” and was arrested.

Despite being only 19 years old and having no criminal record, he was put on trial three times within a year – the first two resulting in hung juries – before being found guilty and convicted of the murder.

Though law enforcement presented evidence linking Ellis to the murder, Ellis always denied any involvement, with his lawyers claiming that Ellis was the victim of a police conspiracy.

As a hugely popular police officer, there was a high amount of pressure to quickly name Mulligan’s killer, with Ellis’s lawyers alleging that the 19-year-old was merely being used as a scapegoat.

Just months after Ellis was convicted, evidence of police misconduct came to light, with two key detectives being accused of mishandling evidence and witnesses in the case, before later pleading guilty to long-term malpractice including perjury and armed robbery. Questions were also raised about the credulity of witnesses.

After first asking for a retrial in 1998, which was denied along with a 2000 appeal, a second retrial motion was submitted by Ellis in 2013.

In 2015, his conviction was overturned by a judge who ruled that “justice was not done” after exculpatory evidence about the handling of his case came to light. Ellis had spent “21 years, seven months and 29 days” behind bars.

Netflix’s statement reads: “Ellis’s story, while devastating, sheds light on timely issues of systemic racism, police corruption and criminal justice reform while offering hope that, ultimately, people have the power to change the system.”

Trial 4 is available to stream on Netflix now.