Aaron Hernandez had just signed a five-year, $40 million contract with a $12.5 million bonus, $50,000 of which he immediately donated to the Myra Kraft Giving Back Fund.

Patriots owner Robert Kraft is one of the brightest, most savvy and influential owners in the NFL, but on that day in late August of 2012, he was tossing bouquets at Hernandez.

“I just think he’s a super player and really a first-class guy,” Kraft said.

Kraft was 1-for-2.

As it turns out, not only is Hernandez sitting in prison after being charged with first-degree murder last June, just 10 months after signing the contract, but he is now also a suspect in the drive-by murder in Boston of two men six weeks before he signed.

Hernandez is changing the way teams do business, which is why the Jets need to immediately ditch any plans they have to sign DeSean Jackson, who was cut by the Eagles on Friday, with stories about an alleged association with gang members swirling around him.

Do the Jets need the potential headache and the fear of more troubling behavior surfacing? Of course not.

Why inherit somebody else’s problem? It’s risky enough investing in players with no apparent red flags. The NFL climate today calls for proceeding with extreme caution.

Can Jackson help the Jets? Of course he can. He is one of the most dangerous deep threats in the NFL and he’s coming off career highs in catches (82) and yards (1,332) and tied his high in TDs (nine). He and Eric Decker would be a nice receiving tandem for Geno Smith/Michael Vick.

But do the Jets need the potential headache and the fear of more troubling behavior surfacing? Of course not.

The Patriots knew Hernandez had issues at Florida, but they believed he had been a good citizen in his first two years with the team before signing him to the extension.

There is no chance Kraft and Bill Belichick would have made that kind of investment if they had an inkling of Hernandez’s dark side. They thought they knew their player and that he had bought into the Patriot Way.

The Eagles had been shopping Jackson because of a reported bad attitude, a bad work ethic and a bad relationship with Chip Kelly. He was due to make $10.5 million this season. Their concern about him reportedly increased this week, and on Friday, NJ.com published a story detailing Jackson’s “continued association with reputed Los Angeles gang members who have been connected to two homicides since 2010.”

After he was released, Jackson issued a statement defending himself and his character. And he denied any gang involvement. “I would like to make it very clear that I am not and never have been part of any gang,” Jackson said. “I am not a gang member, and to speculate and assume that I am involved in such activity off the field is reckless and irresponsible.”

Regardless, the Eagles abruptly cut Jackson on Friday, giving up any attempt to trade him. This could be a Super Bowl year in Philly, and Jackson would have certainly continued to thrive in Kelly’s fast break offense, making it apparent that they had had enough of him.

And if the Eagles, who know Jackson better than any team interested in signing him, didn’t want him, why should the Jets?

This was not a salary-cap dump. This was about the culture change the NFL is attempting to institute. It is all part of the Hernandez Effect. Teams must do their homework and then double- and triple-check it. No team wants its brand stained, certainly not after watching the damage Hernandez did to the Patriot image. Of course, Hernandez is an extreme case, but his alleged criminal acts have put teams on high alert about their players’ off-the-field behavior.