The widow of a cardiac surgeon shot dead at a Boston hospital by his patient's son has given birth to their fourth child, a baby girl, less than three months after the doctor's slaying. Brigham and Women's Hospital announced Monday that Mikaela Jane Davidson was born April 4. Mikaela's father, Dr. Michael Davidson, was killed at the hospital January 20, leaving behind his wife, Dr. Terri Halperin, daughters Kate, 10, Live, 8, and their 2-year-old son, Graham. Scroll down for video . New life: Mikaela Jane Davidson was welcomed into the world April 4, less than three months after her father, Boston heart surgeon Dr Michael Davidson, was shot dead by a deceased patient's son . Heartbroken: Dr. Terri Halperin (left), a mother of fourth, said in a statement her late husband, Dr Michael Davidson (right), was looking forward to meeting his new baby daughter . 'Michael was very much looking forward to the birth of this beautiful baby girl,' Halperin said in a statement released through the hospital. 'At a time when my children and I are completely heartbroken over the loss of Michael, we are finding joy in Mikaela's arrival.' The hospital said the mother and baby Mikaela, who was named after her father, were both doing well. A beloved surgeon who was targeted and fatally shot by gunman at a Boston hospital on Tuesday was expecting his fourth child with his wife, who is seven months pregnant, it has emerged. Dr Davidson, 44, from Wellesley, Massachusetts, was shot by Stephen Pasceri, 55, on the morning of January 20 and passed away late that evening. Pasceri's relatives suggested that he was angry over the death of his mother, whom Dr Davidson had treated. Vendetta: Accountant Stephen Pasceri (left and right) opened fire on Davidson at Boston's Brigham and Women's Hospital January 20. The doctor died and Pasceri, a father of four, took his own life after the shooting . 'You all should be absolutely assured that Michael Davidson was one of the kindest, best possible men that ever walked on this earth,' colleague Dr. Andrew Eisenhauer said at the time, ABC News reported. 'We knew that and his patients knew that and his family knows that.' The gunman, an accountant and married father-of-four, had walked into the heart center and asked for Dr Davidson, before shooting him twice and taking his own life in a separate room. In the days after the tragedy, Davidson's father-in-law told the Boston Herald how the doctor had yelled for patients and staff to flee before he was shot. 'He was a hero - he told everybody to get out,' he said. 'He started yelling, "Get out. Get out." He knew it was coming.' He recalled how much he cared for his patients, and added: 'He loved his family. He loved his kids. He loved my daughter to death.' A fund has been set up for the family here. Left behind: Davidson and his wife Terri, pictured, have two daughters, seven and nine, and a son, two. She was seven months pregnant with their fourth child at the time of the shooting . Mourning: Brigham and Women's Hospital doctors, from the left, Charles Morris, Andrew Eisenhauer, Daniel Wiener and Pinak Shah appear emotional as they face members of the media to speak about Davidson . Pasceri's family have said they can't understand why he snapped, but they believe he could have been wanting to enact revenge on Dr. Davidson after his mother, Marguerite, died last fall. Davidson had treated Marguerite Pasceri for a cardiovascular condition during her stay at Brigham and Women's last year. She died on November 15, 2014. Pasceri, who was licensed to carry a firearm, may have also been holding a vendetta because of the health care his father Greg received during a fatal hear attack in December 2011. The Worcester Telegram reported that in 2012, Pasceri became so furious that his mother had been left with a $8,000 medical bill, he wrote to Senator John Kerry and US Rep. James McGovern to demand an investigation. However, the newspaper noted that the Pasceri family had no issue with the level of care received by their father at Massachusetts General Hospital. Pasceri's sister said she was stunned that her brother had attacked the doctor. Blame game: Marguerite E. (Olofson) Pasceri passed away on November 15, 2014 and it is thought that her son and executor, Stephen Pasceri blamed Dr. Davidson at Brigham and Women's Hospital for her passing . Heartbroken: Administrators and staff at a leading Boston hospital are mourning the death of a cardiac surgeon who was fatally shot at the hospital by a man who then killed himself . Sadness: The hospital's logo flag was lowered to half-staff during a Wednesday ceremony to honor Davidson . 'Everything seemed to be going really well. I have no idea why he snapped like this,' said Marguerite Jolym, according to the Boston Herald. According to Joly, her brother 'deeply loved' his mother and said her 'warm, compassionate, generous and understanding personality was a gift and example to the world'. 'I think it comes down to the fact that my brother thought it was the doctor's fault that my mother died,' Joly said. 'I don't know why my brother would blame him. I really don't know why.' According to the Boston Herald, Pasceri worked as an accountant for Waters Corp, which is based in Milford. Marguerite Joly said her brother served in the military for a time and was honorably discharged and was a married father of four. 'We can't even wrap our brains around this,' she said. 'There was no indication whatsoever that he would ever do anything like this... All his ducks were in a row,' she said. 'This was not a bad, evil man. Something happened, and I don't know what.' Response: Boston Police Superintendent-in-Chief William Gross, (center left), walks through a revolving door as he departs the Shapiro building at Brigham and Women's Hospital on Tuesday after the shooting . Evacuation: Medical personnel walk past law enforcement officials, (right), as they depart the Shapiro building after the cardiologist was shot . Multiple agencies: The FBI, Boston Police Department and the ATF all arrived at the hospital after the incident on Tuesday morning . Boston Police Commissioner William Evans said officers conducting a room-by-room search found the gunman dead in an exam room with the weapon. Shortly after the shooting, one witness said that the Shapiro building had been placed on lockdown and dozens of emergency vehicles had arrived on the scene. 'Once we were clear of the waiting room, there were police officers with their weapons drawn yelling, 'Get down! Get down,'' said one man to WCVB. Boston Mayor Martin J. Walsh said he was 'deeply saddened' by Davidson's death. 'This tragedy is the result of a senseless act of violence that has no place in our City,' he said in a statement a day after the shooting. Hospital employees are well-drilled for the nightmare scenario of a shooter inside the building. In November 2013, doctors and nurses and other staff at the world-famous institution underwent training for an active shooter situation and viewed a video for a so-called 'Code Silver' event.
Dr. Michael Davidson was shot dead by Stephen Pasceri at Brigham and Women's Hospital in Boston in January . Pasceri's sister said he blamed the doctor for his mother's recent death . Married Pasceri took his own life after shooting Davidson at heart center . Davidson's wife, plastic surgeon Dr Terri Halperin, was seven months pregnant at the time with their fourth child . Halperin delivered daughter Mikaela Jane Davidson April 4, less than three months after husband's slaying .