Former National Basketball Association star Alonzo Mourning was just trying to raise some money for his charity. The bad decision he made, it seems, was in the place he picked to do it.

Alonzo Mourning Charities put together a golf event at Trump National Golf Club in Westchester County, N.Y., in August 2010. The gimmick was that anyone who hit a hole-in-one on the club's 13th hole would win $1 million; the fundraising part came from people signing up to give it a shot.

As our David Fahrenthold reported Tuesday, Martin Greenberg's attempt was successful. Mourning himself joined Greenberg on the green for a photo that the basketball star then signed and sent to the contest's winner.

There were some technicalities to work out afterward. A few hours after the event, a representative of the company insuring the contest asked Greenberg to show him where his shot was taken from and measured the distance from that spot to the hole with a range finder. It was 150 yards, the minimum required distance for the contest to be valid.

All Greenberg had to do was sit back and wait for his $1 million check.

It didn't come. The insurer reviewed the claim and photos and video of the shot itself, determining that the position from which Greenberg indicated he'd taken his shot couldn't have actually been the spot where he'd taken it. The back of the tee box was filled with spectators and other accoutrements of the contest that weren't there when Greenberg and the company's representative returned several hours later. The golf pro at Trump National told the insurer that the 13th hole could only measure 150 yards if a golfer teed off from the very back of the tee box. So Greenberg's shot was more like 135 yards, too short to qualify for the million bucks.

Greenberg sued Mourning's charity, the insurer and Trump National. It seems clear, in reviewing the documents, that it was Trump National that was primarily liable for the mistake, given that the golf club was responsible for ensuring that the distance of the hole met the 150-yard minimum. Greenberg settled with the club and Mourning, with the determination that Trump National would make a charitable contribution of $500,000 to a charity of Greenberg's choosing.

That's where Fahrenthold comes in. He's been tracking the money coming into and going out of the Trump Foundation, a 501(c)(3) established by the Republican presidential nominee. He spotted a contribution from the foundation to the Martin B. Greenberg Foundation listed in the foundation's 2012 federal tax filing — a contribution for the sum of $158,000. In his article Tuesday, Fahrenthold noted that the path from a debt owed by Trump National to a payment from the Trump Foundation isn't quite clear, and may not be legal. He quotes Rosemary Fei, a lawyer in San Francisco:

“Yes, Trump pledged as part of the settlement to make a payment to a charity, and yes, the foundation is writing a check to a charity,” Fei said. “But the obligation was Trump’s. And you can’t have a charitable foundation paying off Trump’s personal obligations. That would be classic self-dealing.”

It's worth overlaying other reporting from Fahrenthold noting that the Trump Foundation mostly leveraged money from other people.

By the end of 2006, the Trump Foundation had a grand total of $4,238 in the bank. In 2007, Trump himself contributed $35,000 to the nonprofit and, in 2008, he gave an additional $30,000. Those were the last donations he made through the end of 2014 — the most recent year for which data are available. But the foundation gave out millions in charitable contributions over that period, thanks to donations made by others affiliated with Trump.

The biggest single contribution came in 2007. That year, Vince and Linda McMahon of World Wrestling Entertainment fame gave the foundation $4 million. (The contribution is listed in the foundation's tax filings as having come from WWE itself, which a representative of WWE told The Post is incorrect.) Thanks to that contribution, the foundation ended 2007 with $3.2 million in the bank. It had $3 million at the end of 2008.

At the end of 2011, it still had $2.1 million left over, having collected $6.8 million between 2007 and 2011 (including that McMahon money) and having given out $4.6 million to charities. It's all one big pot of money, so you can't draw a clear line from one incoming contribution to one going back out, but without that McMahon check, the Trump Foundation would not have been able to make the contributions it made from 2007 through the end of 2012. That was the year that the check to Greenberg was issued.

It's not clear why the total was only $158,000. (Fahrenthold reports that Greenberg's foundation didn't get any other money from Trump or Trump National that year.) It's possible that Greenberg requested contributions to other organizations that were also included in the $1.7 million the foundation gave out in 2012.

We do know, though, that in 2010, 2011 and 2012, the Trump Foundation didn't make any contribution to Alonzo Mourning Charities.