Netflix just released a trailer for the upcoming docuseries Trial 4, premiering on the streamer next month. The 8-episode series follows a man named Sean K. Ellis who spent 22 years in prison after being unjustly convicted of murdering Boston Police Detective John Mulligan. [caption id="attachment_942582" align="alignright" width="360"] Image via Netflix[/caption] Ellis was put on trial 3 times within one year before being found guilty of the murder in 1993, when he was 19 years old. His attorneys and supporters long maintained that Ellis was the victim of a police conspiracy, and had simply been …