Massachusetts man found guilty of killing 37-year-old woman who was preparing for child’s birthday

According to the District Attorney’s Office, on Friday, Tyler Sumner was found guilty of Murder in the First Degree and Possession of Ammunition without a Firearm Identification Card by a jury of his peers. The trial was held in Berkshire Superior Court. The Honorable Judge Flannery will schedule sentencing.

Sumner was found guilty of murdering 37-year-old Stephanie Olivieri. In the early morning hours of Sunday, August 25, 2019, Pittsfield Police responded to 911 call reporting two masked men walking around 66 South John Street. While in route, the responding officers heard several gun shots around the area of South John Street. When the officers arrived on the scene, they found a woman, later identified as Stephanie Olivieri, in her running car. Olivieri was gasping for breath and had blood running down the right side of her head. The responding officers called for backup and began lifesaving efforts. Olivieri was treated by EMS on the scene and then transported to Berkshire Medical Center where she was later pronounced dead. The Chief Medical Examiner found the cause of her death to be a homicide caused by wounds sustained from a bullet to her head.

Multiple individuals testified that they believed Tyler Sumner was targeting an individual living in the area of the shooting. They believe that Olivieri was not the intended target of the murder.

Following the shooting, law enforcement conducted a thorough investigation that included gathering multiple pieces of evidence. This evidence included items recovered at and around the crime scene, video surveillance from multiple residences and businesses, witnesses present at the time of the crime, individuals with suspected knowledge of what occurred, and recorded calls from the Hampden County House of Corrections, and a singular text message exchange.

Following the verdict being read, District Attorney Shugrue stated:
“Today justice was served in the tragic death of an innocent bystander, Stephanie Olivieri; however, this guilty verdict will do nothing to bring her back. Tyler Sumner murdered Ms. Olivieri while she sat in a car filled with gifts and decorations for her child’s birthday. She was preparing to celebrate a wonderful event when her life was ruthlessly cut short.

Proving this case against Mr. Sumner presented many challenges for the prosecutors. The tremendous work of the Pittsfield Police, supporting law enforcement agencies, and the victim witness advocates were crucial in allowing justice to be reached. The guilty verdict could never have come without the phenomenal work of Assistant District Attorney Eramo and Assistant District Attorney Winston. Together, they fought throughout the trial and gained justice from the jury.

As the work of our office has demonstrated over the past year and a half, I do not tolerate gun violence. No matter how challenging a gun violence case is, the Berkshire District Attorney’s Office will not back down.

Finally, I want to extend my sincerest thanks to the jury for their dedicated attention over the past two weeks. I commend their work to seek the truth and come to a just verdict.”

Assistant District Attorney Rachel Eramo and Assistant District Attorney Amy Winston represented the Commonwealth. Director of Victim Witness Advocates, Jane Kibby-Peirce, served on behalf of the Berkshire District Attorney’s Office.

The Pittsfield Police Department was the lead law enforcement agency investigating the case. The Pittsfield Police Department was supported by the Massachusetts State Police Firearms Identification Section, the Massachusetts State Police Crime Lab, the Berkshire House of Corrections, the Hampden County House of Corrections, and the Berkshire District Attorney’s Office State Police Detective Unit.