2006: Co-Defendant Freed
Background
The murdered Det. John Mulligan was a man with many enemies. His heavy-handed policing style had earned him a score of police misconduct probes and multiple lawsuits for citizen brutality and false arrest. Police initially considered his gangland-style slaying "a message" from someone bent on revenge. They began a deep dive into Mulligan’s police work.
But after Sean Ellis and Terry Patterson were picked up – two Black teenagers who’d shopped at Walgreens – investigators changed their theory of the case. Now they called Mulligan’s murder a "random crime" committed by youths who wanted to steal his gun for a "trophy."
Terry Patterson, who had no known link to Det. John Mulligan, was speedily convicted of his murder and robbery in February 1995, largely based on fingerprints found on the door of Mulligan’s Ford Explorer that police said were his. He was sentenced to life without parole.
Two subsequent Massachusetts Supreme Judicial Court (SJC) rulings changed Patterson's fate.
2000: Convictions overturned
In 2000, the SJC reversed his murder and robbery convictions based on a conflict of interest by his trial attorney that, ironically, concerned police perjury. He was moved from maximum security Walpole State Prison to Nashua Street Jail to await retrial.
Terry Patterson. In May 2006 he was freed from prison after pleading guilty to manslaughter, armed robbery, and weapons charges and being credited for time served.
2004-05: Fingerprint evidence disallowed
In 2004, Boston defense attorney John H. Cunha, Jr. motioned Suffolk Superior Court to discount the "latent" fingerprint evidence found on Detective Mulligan's car that was used against Patterson. No single latent impression, on its own, could reliably be matched to any corresponding finger on Patterson's hand. Attorney Cunha argued that the Boston Police method of collecting "simultaneous latent prints" from four fingers and adding up their "ridge characteristics" to create a match was invalid, for there were not enough points of comparison for each fingertip.
In December 2005, the Massachusetts Supreme Judicial court agreed with attorney Cunha that the practice used by Boston Police was constitutionally unreliable and not based on generally accepted scientific theory. The "latent prints" purported to be Patterson's were disallowed as evidence -- a stunning legal victory with wide implications, for the court ruled that no prints collected by this method could henceforth be admitted as evidence in the Commonwealth of Massachusetts.
Click HERE for December 2005 SJC ruling on inadmissibility of Patterson’s latent fingerprints.
2006: Patterson released
With the fingerprints the Commonwealth claimed were Patterson's now in the trash bin, the case against him fell apart. Prosecutors crafted an agreement that would allow Patterson to plead guilty to manslaughter, armed robbery, and gun charges, and in return be freed from prison, credited for time served.
Like Sean, Patterson had always insisted he was innocent of Mulligan's murder. Now he was looking at an open prison door if he would sign the Commonwealth's affidavit admitting culpability – and naming Sean Ellis as the shooter.
Patterson signed the Commonwealth’s affidavit and was released from prison.