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Sean Ellis

Other Suffolk County, MA Exonerations
At 3:49 a.m. on September 26, 1993, Steven Bannister, an employee of a Walgreens in the Roslindale section of Boston, Massachusetts, called 911. Bannister said 52-year-old John Mulligan, a Boston Police detective working on a paid police detail providing security at the store and parking lot, was sitting in the front seat of his sport utility vehicle with blood on his face.

Mulligan had been shot five times in the face. His service weapon was missing. The passenger door was locked, but the driver’s side door was unlocked.

A 50-member police task force was put together to solve the crime. The leading investigators were detectives who worked in the same unit with Mulligan.

Bannister said he left the store to get coffee at 3:30 a.m. Mulligan was in his vehicle and appeared to be fine. When the employee returned, he saw the blood on Mulligan’s face and called 911.

Rosa Sanchez told police she and her husband came to the Walgreens at 3:05 a.m. to buy soap. She said she saw a black man crouching next to Mulligan’s SUV. Mulligan was asleep in in the vehicle with the seat tilted back. Sanchez said that she left the store at 3:25 a.m. The man she saw crouching near Mulligan’s vehicle was now standing at a pay telephone with another black man, she said.

Another woman who arrived at the store at about the same time as Sanchez said she saw Mulligan sleeping in his vehicle and two black men walking toward the pay telephone.

Victor Brown, who lived behind the Walgreens, told police that he awoke at about 3:20 a.m. and heard the sound of a diesel engine. He said he saw two men get out of a 1987 chocolate brown Volkswagen Rabbit with tinted windows and walk out of sight. Brown said he thought the men were abandoning a stolen car, so he walked outside. He said there was a woman in the back seat and when he inquired, she said she was fine. Brown said he went back into his house without noting the license plate number. A few minutes later, heard a car door close. He said he looked out his window and saw the car leave at a high rate of speed.

After a delivery driver reported seeing a brown Volkswagen with tinted windows carrying three people—two black men in front and a woman in the back seat—on the road where the Walgreens was located, police appealed to the public for help in finding the car.

Joanne Samuel told police that she and her boyfriend went to the Walgreens to buy socks just before 3 a.m. They saw an officer whom she recognized as the one who typically worked security there. A white woman was sitting in the passenger seat. She said she left the store about 10 minutes later and the woman was still in the vehicle.

Mulligan’s vehicle was processed for fingerprints that day and 17 prints were lifted. Four of them, according to a detective, were left at the same time by the same hand.

On September 29—six days after Mulligan’s murder—Celine Kirk and Tracy Brown were murdered in their apartment in Boston. While police were investigating that crime, they found a package of disposable diapers and a photo identification card for 19-year-old Sean Ellis, who lived in the apartment with Brown. Kirk, Brown, and Ellis were all cousins.

Detectives spoke with David Murray, who was the uncle of Ellis and the two murdered women. Murray said that Ellis told him that he believed a man named Craig Patterson was responsible for the women’s murders. Police subsequently determined that “Craig Patterson” was actually two people—18-year-old Craig Hood and 18-year-old Terry Patterson.

That same day, detectives found a brown Volkswagen matching the description of the car seen near the Walgreens. There were no license plates on the car, and it had scratches and residue that detectives believed were evidence that window tint had been removed. The car was registered to Terry Patterson’s brother, Mark Evans, who told police that Patterson was the primary driver of the car.

Because his identification was found in the apartment where Kirk and Brown were murdered, detectives questioned Ellis on September 30. Ellis said that on the day Mulligan was murdered, he rode his bike to a friend’s house where he hung out with Celine Kirk and Terry Patterson. Before he left the house, he spoke by telephone with Tracy Brown, who asked him to pick up disposable diapers on his way to their apartment. He said Patterson agreed to drive him to the Walgreens.

Ellis said he and Patterson stopped by the pay phone and he called a friend, Harriet Griffith. He gave the detectives Patterson’s pager number and urged them to contact Patterson to confirm his account. Ellis denied having any involvement in Mulligan’s murder.

On October 3, Patterson and his attorney met with detectives. Patterson said he owned a maroon Volkswagen Rabbit with tinted windows. Patterson corroborated Ellis’s account of going to the Walgreens to buy diapers and that they stopped at the pay phone. Ellis also said he pulled over next to a footpath so that Ellis could urinate in the woods, which aligned with Victor Brown’s account of seeing the car that he initially thought was stolen. At the conclusion of the interview, a detective asked Patterson, “Were you the triggerman?” Patterson said, “No.”

Detectives assembled two photographic arrays, each containing eight photographs. One contained Patterson’s photograph and the other contained Ellis’s photograph. On October 5, Rosa Sanchez and her husband, Ivan, went to the police homicide unit where she viewed the photo arrays under the supervision of Detectives Walter Robinson and Kenneth Acerra. Acerra not only knew Sanchez personally, he had a child with Sanchez’s aunt and was a good friend of Sanchez’s mother. He did not disclose this relationship until December.

When Sanchez was shown the array with Ellis’s photo, she became upset because she said one of the eight was someone who had stalked her. That photo was then covered and Sanchez again viewed the photographs. She pointed to someone other than Ellis and said she thought that could have been the person she saw crouching next to Mulligan’s vehicle.

Sanchez left the station but returned an hour later after her husband called detectives to say that she selected the wrong person because she was afraid and did not want to get involved. She viewed the array for a third time and selected Ellis as the person crouching next to Mulligan’s vehicle.

Detectives re-interviewed David Murray. Murray said that Ellis told him that when he came out of the Walgreens after buying the diapers, he discovered that Patterson had moved the car to just off American Legion highway near some bushes. Murray claimed that Ellis told him that Patterson came running across the parking lot yelling at Ellis to get going. When Ellis and Patterson got to the car, Patterson said, “I shot someone.”

On October 6, Patterson and Ellis were arrested on charges of first-degree murder, armed robbery, and two counts of illegal possession of a firearm. That same day, Craig Hood was charged with the murder of Celine Kirk and Tracy Brown. He confessed he killed Kirk during an argument over a gold chain and then he fatally shot Brown when she entered the apartment right afterward.

The following day, police found Mulligan’s service revolver and a .25-caliber pistol in some bushes near Ellis’s home. Ballistics testing indicated the .25 was the gun that killed Mulligan.

On October 18, 1993, Rosa Sanchez identified Ellis in a live lineup as the man she saw crouching next to Mulligan’s vehicle. Ellis was the only person who was in both the photo array and the live lineup. She never identified Patterson.

In late October, after Ellis and Patterson were arraigned, Patterson’s attorney received a copy of an affidavit that had been submitted in support of a search warrant application. That affidavit recounted Patterson’s October 3 interview and included an additional question and answer. The affidavit said that the final question was whether Ellis was the triggerman and that Patterson had nodded his head.

The defense attorney had been present for the interview and realized immediately that affidavit contained a false statement. The defense attorney immediately notified the prosecutor and Ellis’s lawyer that the affidavit had been falsely altered to say that Patterson had implicated Ellis.

As a result, Ellis and Patterson were granted separate trials.

In January 1994, former Massachusetts State Senator Dianne Wilkerson sent a letter to Ellis’s attorneys, Norman Zalkind and David Duncan, reporting that she had received an anonymous telephone call from someone who claimed that Mulligan was shot by his girlfriend after she discovered he was seeing other women. The caller also said the .25-caliber pistol was Mulligan’s personal weapon that he kept in an ankle holster. The caller said he planned to go to the FBI.

In December 1994, a hearing was held on a defense motion by Patterson’s lawyers seeking to bar Sanchez’s identification because of undue influence from Detective Acerra since he had a long time relationship with Sanchez’s relatives. During the hearing, Sanchez again picked Ellis, but when asked to identify the person she said was stalking her, she picked someone other than the person she had selected originally.

The motion to bar the identification was denied.

On January 4, 1995, Ellis went to trial in Suffolk County Superior Court. The prosecution’s theory was that Ellis and Patterson came upon Mulligan, who was asleep, and decided to rob him of his weapon and kill him.

On January 21, after eight days of deliberation, the jury convicted Ellis of two counts of illegal possession of a firearm. However, a mistrial was declared on the first-degree murder and armed robbery charges when the jury was unable to reach a unanimous verdict.

Immediately after, Patterson went to trial in Suffolk County Superior Court. The primary evidence against him was the fingerprint testimony. The fingerprint examiner said that the impressions taken from the door of Mulligan’s vehicle, consisting of four “simultaneous” impressions—made by four fingers from the same hand at the same time—were left by Patterson when he closed the door of the vehicle. During cross-examination, the fingerprint examiner acknowledged that his identification method using cumulative points of comparison from different fingers was not the standard method for fingerprint identification. The prosecution also presented evidence that the day after Mulligan’s murder, Patterson moved the car from its customary parking location to the home of Evans’s brother-in-law. When the police located the car a few days later, they found that its appearance had been altered and its license plate removed.

A detective testified about the interview with Patterson. When questioned by the prosecution, the detective said that the final question was: “Are you the trigger man or is Sean?” The detective said Patterson responded by nodding his head, and that he had then stood up and rolled his eyes toward the ceiling. On cross-examination, the detective changed his testimony. He said he asked Patterson two separate questions: whether he was the triggerman, which he denied and then whether Ellis was the triggerman, to which he had nodded.

Patterson’s trial lawyer did not testify as to her recollection of the contents of the interview, and Patterson did not testify. As a result, there was no evidence offered to refute the detective’s assertion that Patterson had identified Ellis as the gunman. On February 1, 1995, a jury convicted Patterson of first-degree murder, armed robbery, and illegal possession of a firearm. He was sentenced to life in prison.

Ellis went to trial a second time on March 21, 1995. A second mistrial was declared on April 1, 1995 after the jury was unable to reach a unanimous verdict.

Ellis went to trial a third time on September 6, 1995. Sanchez identified Ellis as the man she saw crouching next to Mulligan’s vehicle. She said that she saw two men—one tall and thin, which fit Ellis’s description, and one shorter and heavier, which fit Patterson’s description.

Although other witnesses, including Victor Brown, testified to seeing two black males near the Walgreens at the time of the murder, none was able to identify either Patterson or Ellis.

The evidence that Patterson had been matched to the four prints on the door of Mulligan’s vehicle also was introduced. And the same detective said that he had identified a fingerprint of Letia Walker, Ellis’s girlfriend, on the .25-caliber pistol that was the murder weapon.

Under a grant of immunity from the prosecution, Walker testified that on September 30, 1993—four days after Mulligan’s murder—she went with Ellis to his apartment and he retrieved a bag with two guns, a .25-caliber pistol and a nine-millimeter Glock semi-automatic pistol. She said Ellis gave the guns to Kurt Headen, who hid them in a field. Headen had been killed prior to the trial.

On September 14, 1995, the jury convicted Ellis of first-degree murder and armed robbery. He was sentenced to life in prison.

In February 1996, the Boston Police anti-corruption unit had begun investigating several detectives, including Detective Acerra and Detective Walter Robinson, for robbing drug dealers. The unit had received complaints of corruption that included allegations against Mulligan as well.

In October 1997, a federal grand jury indicted Robinson and Acerra on numerous charges including the falsification of search warrants and theft of thousands of dollars from drug dealers dating back to 1990—three years before Mulligan was murdered. Robinson and Acerra later pled guilty and each was sentenced to three years in prison. Detective John Brazil was granted immunity in return for his testimony that he prepared false affidavits for search warrants and falsely claimed to have performed surveillance when he had not.

In 1998, Ellis’s attorney Rosemary Scapicchio filed a motion for a new trial based on the disclosure of the corrupt activities of detectives who had been involved in the investigation. The motion was denied without a hearing. In December 2000, the Supreme Judicial Court upheld the dismissal, holding that there was no proof that the detectives had falsified any evidence in the Mulligan investigation.

That same month, the Supreme Judicial Court reversed Patterson’s convictions. The court held that Patterson was deprived of crucial evidence when his defense attorney failed to step aside and be called as a witness to rebut the police version of Patterson’s interrogation.

Prior to a retrial, Patterson’s lawyers challenged the “simultaneous impression” fingerprint evidence as unreliable. The trial court denied the motion, but in 2005, the Supreme Judicial Court reversed and said the fingerprint evidence would not be allowed at the retrial.

In February 2006, Patterson pled guilty to manslaughter. He was released in 2007 after receiving credit for time served.

In 2010, Scapicchio sought assistance from the Massachusetts Committee for Public Counsel Services Committee’s Wrongful Conviction Review fund. The case was accepted, and the PCSC provided funds for the investigation and public records requests.

In March 2013, Scapicchio filed a second motion for a new trial alleging the prosecution and police had failed to disclose to the defense evidence of other possible suspects. The motion also alleged that the state failed to disclose evidence, including FBI reports, that Mulligan was deeply involved in the corrupt activities of Robinson, Acerra, and Brazil.

Further investigation ensued. At a hearing, evidence was presented that a police officer had told police not long after Mulligan’s murder that another police officer was responsible for the murder. One theory was that Mulligan was murdered to keep him from cooperating in any investigation of the corrupt activities in which he and the others were engaged.

Among the reports was a statement from Detective George Foley. Foley said that in August—prior to Mulligan’s murder—Ray Armstead, Jr., who was a corrections officer, confided in him that Armstead’s father was going to kill Mulligan. He said that Mulligan, who had a reputation for being attracted to young girls, would not leave Armstead’s 14-year-old sister alone.

Foley said he told Armstead he would talk to Mulligan about it, but Armstead said it was “too late.” They knew Mulligan slept in his car while on duty at the Walgreens. “You are going to read about [it] in the papers. Shot between the eyes at [Walgreens].”

Police reports showed that Armstead had been questioned about the conversation, and that he denied it ever occurred or that he had a 14-year-old sister. The prosecution denied the report was credible. It noted that Foley later recanted, then insisted it was true, and then recanted and ultimately was hospitalized for psychological treatment.

Other reports showed that 17 days before Mulligan was murdered, he was part of a team of detectives that stole $26,000 from a drug dealer. The FBI had a report from an informant saying that Mulligan regularly shook down drug dealers, prostitutes, and pimps for money, blackmailed other police officers, and had committed murder.

The defense also presented evidence of numerous tips made to a police hotline after Mulligan was killed. One of the tips involved Armstead.

In May 2015, Judge Carol Ball granted the motion for a new trial. In a 67-page decision, the judge ruled that the newly discovered evidence showed that the police “failed to vigorously pursue other leads.” This failure, when combined with Acerra, Robinson and Brazil’s “conflict of interest,” formed the basis of a strong defense. The prosecution, the judge declared, was a “rush to judgment.”

Judge Ball wrote that Acerra, Robinson, and Brazil were involved in “nearly every aspect of the homicide investigation,” and had a personal interest in solving the murder as quickly as possible to prevent other officers not involved in the corrupt activities from discovering what Mulligan and the others had been doing. Judge Ball did not vacate Ellis's gun convictions from the first trial.

On June 3, 2015, Ellis was released on bond while the prosecution appealed Judge Ball’s ruling. In September 2016, the Supreme Judicial Court upheld the ruling, paving the way for a fourth trial for Ellis.

However, on December 17, 2018, Suffolk County District Attorney John Pappas said the prosecution would move to dismiss the charges, saying that “the passage of more than two and a half decades has seriously compromised our ability to prove it again.” On December 18, the motion was granted and the charges were dismissed.

– Maurice Possley

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Posting Date: 12/31/2018
Last Updated: 11/16/2020
Most Serious Crime:Murder
Additional Convictions:Robbery, Gun Possession or Sale
Reported Crime Date:1993
Age at the date of reported crime:19
Contributing Factors:Mistaken Witness ID, False or Misleading Forensic Evidence, Official Misconduct
Did DNA evidence contribute to the exoneration?:No