CHICAGO (AP) — He’s the father of a war hero whose name is familiar to anyone who has flown in and out of Chicago, and his death has been linked to one of the city’s most famous residents ever: Al Capone.

Now the police department’s cold case unit has agreed, at the request of an alderman, to take another look at the unsolved gangland-style 1939 slaying of a prominent businessman Edward J. O’Hare, a case the deputy chief who oversees the unit acknowledged Tuesday is far colder than any other case under investigation.

How much time or how many detectives will actually be assigned to the investigation is unclear, Deputy Chief Al Wysninger said. But while he recognizes the difficulties that come with a case that dates back seven decades, he sounded like he’s taking the task seriously.

“The Chicago Police Department doesn’t close homicides,” he said. “We will try to come to a resolution.”

Still, Alderman Edward Burke isn’t expecting much more from detectives than dusting off the file and looking into whether there is anything left to do with the case.

Capone, after all, has been dead for decades. And even on the off chance anyone connected to the case is alive — a remote possibility given the life expectancy for mobsters of the 1920s and 1930s — they’d be in their 90s.

“They’re not going to waste a lot of time on something that happened in 1939,” Burke said of police.

Instead, Burke sees the exercise as a chance to shine light on one of the darkest chapters in the city’s history, give someone who helped bring down Capone the credit he deserves and tell a story of a father’s love for a son whose heroics a few years later in World War II prompted the city to name its busiest airport after.

“We have the responsibility to set the record straight,” said Burke before the hearing, comparing this effort to how the council in the 1990s absolved Mrs. O’Leary’s cow of blame for the Great Chicago Fire of 1871. “Millions fly into O’Hare (International Airport) every day and they don’t know the story behind the story.”

Edward J. O’Hare, who owned race tracks, had a stake in the old Chicago Cardinals football team, became an informer against his business partner Capone, Burke said. The information O’Hare gave prosecutors was instrumental in Capone’s conviction on income tax evasion.

And, he said, one possible reason is that he wanted to help his son, Edward “Butch” O’Hare, gain admittance to the U.S. Naval Academy and was afraid that his reputation as someone who did business with Capone might hurt his chances.

“It’s an intriguing Chicago legend,” Burke said before the meeting.

Edward “Butch” O’Hare went on to become a Navy pilot, and was awarded the Medal of Honor after shooting down five Japanese bombers and damaging a sixth, preventing them from attacking an air craft carrier. He was later killed in action.

Jonathan Eig, a best-selling author who addressed O’Hare’s slaying in his book “Get Capone,” which is due out in April, said that while Edward J. O’Hare did provide information about Capone, there is no evidence he was doing so to help his son.

“There’s a chance he had his own tax problems and he was involved in a bootlegging case (in which) he got off when everybody else was convicted,” he said after the hearing. “He may have made a deal.”

Nor does he believe, as Burke suggested, that Capone, from his prison cell in Alcatraz, ordered a hit on O’Hare, who was killed about a week before Capone was released from prison.

Capone’s brain was ravaged by syphilis at the time and while he was heard railing about his enemies, Eig said there is no record of him talking about O’Hare.

But, Eig said, there is a possibility that Capone’s family members, who had their own money problems at the time, asked O’Hare for money. Or maybe Capone’s henchman, Frank Nitti, demanded money from the very successful O’Hare, he said.

Whatever the reason, on Nov. 8, 1939, O’Hare was in his car on the city’s southwest side when somebody armed with a shotgun killed him. Nobody was ever arrested for the slaying.

“History deserves that there be a true depiction of what happened,” said Burke.