At a major conference of police officials in San Francisco two years ago, former Chicago police Superintendent Garry McCarthy's phone rang constantly. Each time, it was his boss: Chicago Mayor Rahm Emanuel.

"This is the fifth call I've gotten from him today. This is my life with this guy," he told a former NYPD colleague at the conference. "He knows I am out of town. He tortures me. He's a micromanager. He's like [Rudy] Giuliani on steroids."

After the conference, McCarthy took a few days to travel north through wine country with his soon-to-be second wife. It was there he suffered a heart attack.

"This was a healthy man," said a former top NYPD official. "He worked out every day." He and other former NYPD colleagues attribute McCarthy's heart attack, in part, to the pressures from Emanuel.

McCarthy could also be volatile. In 2005, as an NYPD deputy commissioner, he was arrested and disarmed by a Palisades Parkway police officer after protesting a parking ticket given to his daughter. The incident escalated when his then-wife grabbed McCarthy's confiscated gun from the arresting officer.

But he was also regarded in the NYPD as an aggressive, intelligent and community-minded officer. "He came up with a program to close off streets to drug dealers," said a former top NYPD official. "An integral part of the plan involved community cooperation."

Last week, NYPD police sources say, McCarthy was blindsided by Emanuel, who fired him Dec. 1. During his four years in Chicago, the sources say, McCarthy repeatedly told former NYC colleagues, "The mayor has my back."

The morning of his firing, he was on a TV show, apparently with Emanuel's approval, the sources say. An hour later, Emanuel fired him. McCarthy's dismissal came days after a court ordered the release of a police video that shows white Chicago police Officer Jason Van Dyke shooting black teenager Laquan McDonald 16 times. The video was shot 14 months ago during Emanuel's hard-fought re-election campaign.

The video appeared to contradict police reports that Van Dyke feared for his life from the 17-year-old McDonald. Van Dyke maintained McDonald wielded a knife in an "aggressive and exaggerated" manner. Federal prosecutors are now investigating the department.

Also, a Burger King manager said police deleted 86 minutes from the restaurant's security camera, including the time when Van Dyke fired at McDonald.

Because of the furor over police departments' relationships with black communities nationally, McCarthy's firing has received national attention. President Barack Obama, for whom Emanuel served as chief of staff, has weighed in. His spokesman, Josh Earnest, appeared to justify McCarthy's firing and to support Emanuel, saying: "The mayor has obviously confronted this situation . . . quite directly and already taken some steps to indicate his own commitment."

Perhaps Earnest or the president can explain what "steps" or "commitment" Emanuel has taken, other than firing McCarthy -- and protecting himself.