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Taken one at a time, the reasons the Philadelphia Eagles decided to release wide receiver DeSean Jackson, who had a career-best season statistically in 2013, are difficult to understand.

But put them all together—an open association with gang members, lavish spending, a dispute with former agent Drew Rosenhaus over money, a robbery at his home in January and an often immature approach to his football career—and the decision begins to make sense.

It also explains why that same pattern of behavior has several other NFL teams hesitant to sign him.

And those reasons don't include one other. Several sources close to Jackson and the Eagles say he received a death threat in 2012 from a "crackpot fan.'' Unfortunately, those same sources say that such a threat is not unusual. But what is concerning about this one was Jackson's reaction to it.

"It freaked him out,'' a former associate of Jackson's said. "He thought it was gang (related) at first.''

The Eagles declined to comment on the death threat, and Jackson’s publicist did not respond to a question about the threat.

However, two of those sources believe the threat shook Jackson because of his friendship and association with Los Angeles-area gang members.

Moreover, NFL teams are now researching Jackson’s background and a pattern of events in his life that make them wonder if he can be depended upon.

"Is he a gangbanger? No, I don’t think so," said an AFC team executive with knowledge of security checks on Jackson. "Our belief is that he’s kind of a wannabe, at worst. He hangs out with bad guys because he thinks it’s cool, but he doesn’t really do bad things."

However, as the executive acknowledges, the question NFL teams face now is: Does that ever change?

In the aftermath of the arrest of former New England tight end Aaron Hernandez, NFL teams are taking extra caution with a "fairly significant" number of players who have gang ties. While this has been a focus of NFL security for years, the belief is that most players were largely left alone by gangs and allowed to conduct their careers.

"Most of what we were running into were requests for money, often with a direct or indirect threat of harm to a family member. Basically, protection money. That happens a lot in all sports," a source within NFL security said.

With Jackson, the big concern is whether his tendency to live large will drive him into a troubling place. Jackson has started his own rap label, Jaccpot Records, a venture that is notoriously risky. In Jackson’s case, the risk may go beyond simply financial.

It was reported last week by NJ.com that Jackson has a business relationship/friendship with Theron Shakir, who Los Angeles police believe is a Crip gang member and who was once held for a year after being accused of murder. Shakir has recorded music under Jackson’s record label, and the two have been pictured together twice on social media.

Jackson’s publicist issued a statement after the story appeared on Friday denying any gang membership. The Eagles released Jackson at the same time the story appeared.

As the AFC personnel executive said, "That has some people wondering what’s going on. The timing is really suspicious."

In addition, Rosenhaus has claimed in an arbitration overseen by the NFL Players Association that Jackson owes him more than $1 million in back fees and loans. Jackson has countered that Rosenhaus broke NFLPA regulations by inducing him to sign a representation agreement and that he should be under no obligation to pay Rosenhaus.

In January, police said Jackson's Philadelphia home was robbed, including cash, jewelry and two guns. The cash amount was initially reported to be $250,000, although police have since revised that to only $20,000. However, Jackson offered a $50,000 reward at one point for what was taken.

Beyond all of that, there is the question of Jackson’s behavior around the team. Jackson’s performance in practice and games has been scrutinized since the time he was in college. He dropped to the second round of the draft because of concerns over his attitude and work ethic. He ran into problems with former Eagles coach Andy Reid at times, although Reid continues to be a fan of Jackson as a player.

This past season, Jackson excelled in Chip Kelly’s offense, making 82 receptions for 1,322 yards and nine touchdowns. After the season, Jackson hinted that he wanted a new contract only two years after signing a five-year, $48.5 million deal. Jackson quickly denied he wanted a new deal, but his fascination with his contract and money have been consistent in his career.

Throw in all the other issues, and you have the odd case of an extremely talented player getting cut seemingly at the top of his game. Normally, a player like this might have lasted a day on the open market. Instead, teams are taking their time to make sure they know everything about Jackson’s life.

"Talent? No question, it should be a bidding war. He probably would be signed already if it was just on talent. But it's not, and that should tell you something," the AFC executive said.