A man convicted of killing Boston Police Detective John Mulligan 21 years ago is seeking a fourth trial after two mistrials — the third jury ultimately finding him guilty of first-degree murder.
Sean Ellis allegedly shot Mulligan five times in the face as the detective sat in his vehicle while working a detail outside a Walgreens store in Roslindale in 1993.
Ellis had placed himself at the scene, days after the Mulligan shooting, while being interviewed by police about the unrelated murders of his two cousins. Ellis provided police a sales receipt showing he'd been at the Walgreens the night of the murder.
"Sean had nothing to hide," said his lawyer Rosemary Scapicchio. "Normally somebody who is involved in a homicide isn't going to put themselves in the middle of a homicide with a receipt that means that they were there."
Whether Ellis is granted a new trial will depend on the defense's claim that Ellis had no knowledge of a police report that blamed the murder on someone else. The report shows that cop George Foley came forward to say he'd been told another officer planned to kill Mulligan.
"Had [the defense team] known about the Foley report would have asked some additional questions about what it was all about, how it happened, why is one cop blaming another cop for Mulligan's murder," Scapicchio said. "It would have opened up in my mind more evidence fodder for them to request those internal affairs Boston police documents that they were unable to get prior to trial."
Scapicchio eventually obtained the Foley report from the FBI, after filing a Freedom of Information request.
But, prosecutors insist they did turn the report over to Ellis' lawyers at the time of his trials.
Ed Zabin, chief of the homicide unit for the Suffolk County District Attorney's Office, said prosecutors back then took all of the appropriate steps.
"You follow it up, you interview, you document and you turn it over to the defense attorney and that's what we did," he said.
The report of police involvement in the murder of another officer is not credible, Zabin said.
Ellis' lawyer alleged that three weeks before he was killed, Mulligan was involved with other officers in stealing thousands of dollars from a drug dealer under the guise of a drug arrest.
"There are many things about the statement that are sort of inherently implausible — and there are various facts about it don't make a lot of sense," Zabin said. "The most notorious cop killer in the city I know who did it...that in and of itself calls into question the veracity of the claim..and a detective from the Boston Police Department's internal affairs unit has testified that the officer who came forward had issues with mental illness and alcoholism."
To decide this issue, Judge Carol Ball says she wants to hear from Ellis' trial lawyers and from the former assistant district attorney who prosecuted Ellis. But it's still unclear when any of them might be available.
This segment aired on August 27, 2014.