Nov. 19 (UPI) -- A shooting at a Chicago hospital Monday left four people dead, including a police officer and the suspected gunman, the Cook County Medical Examiner's Office said.
Also killed were an emergency room doctor and a pharmacy assistant at Mercy Hospital on the south side of Chicago, WLS-TV reported.
The Chicago Police Department's chief communications officer, Anthony Guglielmi, identified the slain officer as Samuel Jimenez. He had been transported to University of Chicago Hospital in critical condition.
"Please pray for his family, his fellow officers [and] the entire Chicago Police Department," he tweeted.
A police spokesman told the Chicago Tribune the shooter died of a gunshot to the head.
The shooting began around 3 p.m. A Chicago Fire Department spokesman told the Chicago Tribune that officials sent at least 15 ambulances to the hospital in response to the "active shooter" situation.
Johnson said the incident started in the hospital parking lot as a verbal altercation between the shooter and Dr. Tamara O'Neal, who were "in a domestic relationship."
After a friend tried to intervene in the argument, the shooter lifted his shirt and displayed a handgun. As the friend fled into the hospital, the shooter shot the doctor, Johnson said.
During the exchange inside, a pharmaceutical assistant exiting an elevator was fatally shot.
The hospital tweeted around 4:40 p.m. that police had cleared the facility and deemed it and the other patients safe.
Jimenez joined the force in February 2017 and had just finished his officer probationary period, police Supt. Eddie Johnson said at a Monday night news conference. Jimenez and his partner were assigned to another location and responded to officers needing assistance.
"Those officers that responded today saved a lot of lives," Johnson said. "They were heroes because we just don't know how much damage [the shooter] was prepared to do."
The body of Jimenez, who was a married father of three, was taken by ambulance from University of Chicago Hospital to the Cook County morgue. Federal, state and city law enforcement were lined up to pay their respects during the processional.
"Every one of us will celebrate time with our family in the holidays," Emanuel said. "We have a member of the Chicago family who, on this holiday and other milestones of their family, will not be there."