Updated 03/30/11 – 10:00 p.m.

ORLAND PARK, Ill. (CBS/WBBM) — On this day 30 years ago, gunman John Hinckley shot and wounded President Ronald Reagan and three others.

WBBM Newsradio 780’s Bob Roberts spoke with the former Secret Service agent who “took a bullet” for the president that day – Tim McCarthy, who has been the police chief of Orland Park for the past 18 years.

LISTEN: Newsradio 780’s Bob Roberts reports

“It changed for one reason. It was on videotape,” McCarthy said.

Hinckley fired six times, striking President Reagan, who was then just 69 days into his first term. He also struck White House press secretary James Brady, and Washington, D.C., Police Officer Thomas Delahanty.

McCarthy, the son of a Chicago Police officer from the South Side, was at the President’s side when the shots were fired. McCarthy instinctively dove in front of the President and was hit in the chest. But he still pushed the president into the car, out of harm’s way.

McCarthy has become quite a familiar figure around the Chicago area, but every time you sit down with him, you learn something new about what happened 30 years ago.

When McCarthy sat down with CBS 2 Chief Correspondent Jay Levine on Wednesday, we learned that McCarthy was really an accidental hero.

“I did what needed to be done that day,” Mccarthy said.

McCarthy saw Hinckley with a gun and realized the only way to stop him from shooting Reagan was to stand in front of the president.

“That’s what you’re trained to do, cover and evacuate,” McCarthy said.

McCarthy is the son of a Chicago police sergeant and he knew from the start what he wanted to do.

After joining the Secret Service, he made a career of protecting presidents, including Jimmy Carter, Ronald Reagan, and George Bush.

But McCarthy was at the Washington Hilton to save President Reagan’s life because he lost a coin flip over which of two agents would be protecting the president that day.

“It was pouring rain out, quite frankly, that day when we left. I had a new suit on that day, which was unusual. The follow-up car was convertible with plastic roof on it that leaked,” McCarthy said.

“And I said, ‘You know, I wouldn’t mind staying back’ and so he said ‘Well, let’s flip a coin.’ So we flipped and Joe Trainor, who won the toss said, ‘I’ll just stay back, you go,’” McCarthy added. “And Joe went on to win a couple million dollars in the Pennsylvania state lottery, too, so he’s got a horseshoe in his back pocket.”

Even though he was wounded in the shooting, McCarthy said he’s glad he lost that coin toss.

“Only in the sense that I was able to do the job that day. I was tested and you never know if you’re going to do it right,” McCarthy said.

McCarthy was released from the hospital before President Reagan.

“I got just about out the door and the president says ‘Hey Tim, by the way, listen. It was McCarthy, Reagan, Delahanty, Brady. What the hell did this guy have against the Irish?” McCarthy said with a laugh.

Hinckley was found not guilty by reason of insanity for the shooting after trial in 1982. His motive was reportedly to impress actress Jodie Foster.

McCarthy says the incident effectively silenced critics of increased presidential protection.

“I don’t believe it’s any coincidence that since metal detectors were employed, that there hasn’t been another attack on the president by the historic assassin who’s the lone gunman,” McCarthy said.

McCarthy says he is just glad his training worked, and that he survived to be able to tell the story.

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