MILLBURY — Stephen D. Pasceri apparently “lost it” and fatally shot a cardiovascular surgeon at Brigham and Women’s Hospital because he suspected that medication his mother took during her most recent illness led to her death two months ago, Pasceri’s brother said Wednesday.
Gregory Pasceri said that in a meeting with his family last month, his brother said he believed the medication had “toxic side effects” and could cause pulmonary bleeding, which would have been devastating for their mother, given her past lung problems.
Authorities have not disclosed a motive in the killing. But Gregory believes his brother felt so betrayed over the medication that he walked into the hospital Tuesday morning and shot Dr. Michael J. Davidson before taking his own life.
Davidson, 44, had operated on Marguerite Pasceri for a leaky heart valve sometime before her death on Nov. 15, Pasceri’s relatives said. She was 78.
“He was the surgeon,’’ Gregory said. “I don’t know if he prescribed it, but he must have OK’d it.’’
The death of their mother “destroyed my brother,” Gregory Pasceri said.
Gregory Pasceri said he did not see any signs that his older brother, who lived in Millbury, was about to turn violent. “He was a good guy,” said Gregory, 52.
He said he knew his brother owned a firearm, but was told years ago that it was disassembled and its components were stored separately at Stephen Pasceri’s house. Pasceri was licensed to carry the weapon.
Gregory Pasceri portrayed his brother as particularly close to their mother and father. As the oldest of four children, he forged tight bonds with his parents as the first of his siblings to reach milestones like marriage and children.
Stephen Pasceri, 55, was “instrumental” in his mother’s life, visiting her at least a few times a week at her home in Worcester.
Gregory Pasceri said his mother had suffered from several health problems. She was diagnosed with emphysema in the 1980s and had chronic obstructive pulmonary disease.
In 2003, she twice underwent heart surgery; one procedure detected a 90 percent blockage in one of her arteries, Gregory Pasceri said.
After the procedure, she swore off smoking and enjoyed generally stable health until she started having breathing problems last year, he said.
In the fall, she underwent a heart procedure at the Brigham after she started complaining about breathing problems, Gregory said. He said he was told the surgery went well, but his mother fell ill while en route from the Brigham to a rehabilitation facility in the Worcester area.
At that point, she was taken to Saint Vincent Hospital in Worcester, where she steadily declined and eventually was put on a breathing tube, her son said. Her lungs were filling with blood and she died within minutes of being taken off a ventilator, he said.
Her death certificate lists the cause of death as “cardiovascular collapse” due to congestive heart and kidney failure and a type of respiratory failure associated with chronic obstructive pulmonary disease.
Stephen Pasceri was named executor of his mother’s will, which left about $10,000 to her four children in even shares, according to court records.
A Saint Vincent spokeswoman did not respond to messages Wednesday.
In 2011, Gregory Pasceri said his father, also named Gregory, died suddenly in his sleep. His death, he said, marked the first time he had seen his older brother, Stephen, cry.
Stephen Pasceri “was a really good guy,” said Kellie-Ann McGann, who is Gregory Pasceri’s longtime partner. “This man has only done nice things.”
Stephen Pasceri served in the Army from 1977 to 1981, spending some time in South America, his brother said. The military transformed him from a hippie to a more “strait-laced” person, he said.
He worked as a security guard and accountant, he said, before he signed on with a Milford company, Waters Corp.
He married his wife, Teresa, a hospice nurse, more than 30 years ago, after being introduced to her by two of his siblings, Gregory Pasceri said.
The couple have four adult children, including a daughter, Angela, who lived in an apartment above her grandmother, Marguerite, and a son who is a teacher.
Two of his daughters have also been involved in missionary work, Gregory Pasceri said.
On two occasions, Stephen and Teresa sought relief from the courts when financial problems arose.
In one lawsuit, the couple sued Pasceri’s aunt and uncle over a four-unit property they purchased from them. The suit alleged the home was illegally converted into a multi-family residence and required costly changes.
The house was sold at auction after the couple fell behind on mortgage payments. The couple claimed they lost $37,000 in equity and $50,000 in bills and rental income because their relatives did not sell them a “legal” piece of real estate, the suit said.
In 2001, they filed for bankruptcy protection, saying they had a combined income that year of $27,000, compared to $75,000 the year before, court records show.
Gregory said that he wished his brother had taken up his recent offer to visit him at his new home in Princeton, where he might have found some peace.
“I can’t believe he did that,’’ he said. “It doesn’t make any sense.”
Laura Crimaldi can be reached at email@example.com. Follow her on Twitter @lauracrimaldi.