By KIM BAER

The man had a gun and it was aimed at John Wills.

The gunman fired.

Wills heard the report. He felt the impact, like a sledgehammer hitting his chest.

He didn't have a bullet-proof vest. They weren't issued to police officers in 1975 in Chicago.

He did have his weapon out. He returned fire.

"It was just instinct," Wills recalled. "I didn't even aim."

The suspected robber died shortly after Wills fired.

Wills' partner that night saw the exchange of gunfire. He fired at the man, too.

His bullet landed in Wills' right leg.

Wills spent 10 days in the hospital, recovering from the two gunshot wounds.

Wills, who now lives in Spotsylvania County, recounted this experience in "True Blue: To Protect and Serve."

The book is a compilation of true stories about the profession written by law enforcement personnel across the country.

Published by St. Martin's Press, the book is available through the National Law Enforcement Officers Memorial Fund's Web site at nleomf.com.

MUSEUM TAKING SHAPE

Some of the book's proceeds will go to help build the National Law Enforcement Museum, said Randy Sutton, a longtime Las Vegas police officer who compiled the stories.

The museum is scheduled to open in Washington in 2011, according to a press release on nleomf .com.

Plans for the propos-ed 95,000-square-foot museum include exhibits "where visitors walk in an officer's shoes," according to the release.

Organizers are trying to raise $80 million for the museum, the release said. They've raised about $33 million, the release said.

Wills said he donated his $200 author's fee to the effort.

SAVING LIVES

He recalled the details of that Friday the 13th shooting in 1975 at the Church's Chicken fast-food restaurant in a recent phone interview.

He and his partner responded to a silent alarm at the restaurant, he said. The restaurant was supposed to be closed for the night.

After Wills got into the restaurant, he crept down a hallway. A man was pointing a gun at two of the store's employees, he wrote.

"He was yelling at them to open the office door so that he could get to the safe."

The gunfire exchange followed.