ESPN
In the report, a Los Angeles Police Department detective Eric Crosson alleges that Jackson used a gang sign during the Eagles' nationally-televised, season-opening game against the Washington Redskins (see GIF below).
"You don't want to see anybody throwing up gang signs like he did in the Redskins game last year," Crosson said. "Those were neighborhood Crip gang signs and he flashed them during a game. He may not be affiliated with the gang, but they don't [ordinarily] take kindly to those not in the gang throwing up those gang signs."
Jackson released a statement denying that he is in a gang. Here is a portion of that statement (via ESPN):
"I would like to make it very clear that I am not and never have been part of any gang. 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. I work very hard on and off the field and I am a good person with good values. I am proud of the accomplishments that I have made both on and off the field. I have worked tirelessly to give back to my community and have a positive impact on those in need. It is unfortunate that I now have to defend myself and my intentions. These reports are irresponsible and just not true ."
The incident that Crosson appears to be referring to occurred following a 14-yard catch in which Redskins cornerback DeAngelo Hall was flagged for hitting Jackson late out-of-bounds. Some at the time believed it was a gang sign.
Jackson shoved Hall and the two players continued to yell at each other as they lined up for the next play when Jackson used this hand gesture.
Here it is a full speed which shows that the gesture was very brief.
In light of the recent allegations against former Patriots tight end Aaron Hernandez, teams may be much quicker to act on allegations of gang association.