CHICAGO — A man who fatally shot his ex-fiancee outside a Chicago hospital before killing two people inside the building was once kicked out of the city’s firefighting academy after threatening a female cadet, officials said Tuesday.

Juan Lopez, who died following the shooting Monday at Mercy Hospital, was also the subject of a protection order request filed four years ago, and he legally purchased several guns in recent years, police said.

It was unclear whether Lopez shot himself or was fatally shot by police.

Four years ago, fire department officials learned of the threats to the cadet and told Lopez that he would be disciplined. He was dismissed after he went AWOL, fire department spokesman Larry Merritt said.

Merritt did not have any details of the past threats. But they were made the same year a woman sought an order of protection against Lopez because he was incessantly texting her. Police said they have not determined if the woman was granted an order of protection. Lopez was not criminally charged.

On Monday, Lopez’s first victim was Dr. Tamara O’Neal, to whom he had been engaged. O’Neal had recently called off their engagement, and Lopez confronted her about returning the engagement ring, police said.

After shooting the emergency room doctor near a hospital parking lot, the gunman ran into the medical center, where he continued firing. The gunshots killed a police officer and a pharmacy resident, authorities said.

Lopez had a permit to possess a concealed firearm, but it was unclear if officials knew about the 2014 complaint when the permit was granted, Chicago police spokesman Anthony Guglielmi said.

Lopez had legally purchased four guns in the last five years and worked for the Chicago Housing Authority, Guglielmi said.

Investigators identified the other shooting victims as Dayna Less, 25, who worked in the hospital’s pharmacy and had recently graduated from Purdue University, and Officer Samuel Jimenez, 28, who joined the department in February 2017 and had recently completed his probationary period. Police said he was a married father of three children.

“This officer, all of those officers, are heroes. They saved a lot of lives because we just don’t know how much damage he was prepared to do,” Chicago Police Superintendent Eddie Johnson said late Monday outside another hospital, just minutes after leaving the slain officer’s family.