Tamara O’Neal, a 38-year-old emergency room physician at Chicago’s Mercy Hospital, was killed Monday after her former fiancee showed up at the hospital and opened fire. A police officer and a bystander were also killed, and the gunman died at the scene.

O’Neal was killed in the parking lot, after a domestic argument involving the gunman — identified by police as her former fiancee, 32-year-old Juan Lopez — broke out.

When a friend attempted to intervene, Lopez lifted his shirt to display a handgun, Chicago Police Superintendent Eddie Johnson said. According to the Associated Press, O’Neal’s friend then “ran into the hospital to call for help, and the gunfire began seconds later.”

A family member told ABC 7 Chicago that Lopez and O’Neal were engaged for about a year but that their wedding was called off in September. The Chicago Tribune reported that O’Neal had broken off the engagement and that Lopez went to the hospital Monday afternoon to demand his ring back.

According to the AP, the gunman fired at a police squad car when they arrived on the scene, and then ran inside the hospital, where he exchanged fire with officers and shot a woman who had just come off the elevator.

Police Officer Samuel Jimenez was killed during the shootout, police spokesman Anthony Guglielmi confirmed. Jimenez had joined the department in February 2017. He was married and had three children.

Dayna Less, a 25-year-old pharmacy resident and bystander, also was fatally shot as she left an elevator, authorities said. ABC 7 reported that Less was a graduate of Purdue University and was planning on traveling home to Indiana on Tuesday to be with her family on Thanksgiving. She was engaged and set to be married next summer.

“The city of Chicago lost a doctor, pharmaceutical assistant and a police officer, all going about their day, all doing what they loved,” Mayor Rahm Emanuel said, fighting back tears after the shooting. “This just tears at the soul of our city. It is the face and a consequence of evil.”

It was not immediately known whether Lopez killed himself or died by police fire.

‘Aggressive and improper conduct toward females’

According to the Chicago Tribune, Lopez had threatened to shoot up the Chicago Fire Academy nearly five years ago, after he was terminated for “improper conduct” toward women there.

Fire Department spokesman Larry Langford told the Tribune that Lopez was accused of “aggressive and improper conduct toward females at the academy,” leading to his firing.

“He had issues, he was not getting along well,” Langford said. “He did not successfully complete his training and was terminated before he finished the academy.”

A string of shootings

Also Monday, according to the St. Louis Post-Dispatch, police in suburban St. Louis were searching for a gunman who they say went into a religious supply store, sexually assaulted at least one woman and shot a woman in the head, leaving her in critical condition at a hospital.

The shooting occurred about 3:15 p.m. at a Catholic Supply store in western St. Louis County, near the town of Ballwin. Police were searching for the gunman and said he should be considered armed and dangerous.

In Philadelphia, two men and two women were “executed” in a home, according to ABC. And in Denver’s Lower Downtown neighborhood, one person was killed and at least three others were sent to a hospital after a shooting, according to the Denver Post.

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