The NFL, concerned that some players might celebrate by flashing the hand signals of street gangs, has hired experts to examine game tapes and identify the gestures.
Ahlerich says the league has long warned its players about the influence of gangs and other forms of organized crime, but that those admonishments have intensified since the 2007 killing of Denver Broncos cornerback Darrent Williams, who was gunned down after an altercation involving known gang members.
The issue of athletes flashing signs gained national attention in April when Paul Pierce of the Boston Celtics was fined $25,000 by the NBA for making "menacing gestures" as he walked toward the Atlanta Hawks' bench during a game.
While acknowledging that he wasn't "into the etymology of gestures," NBA Commissioner David Stern took immediate action after league officials examined video of the incident.
"And our decision is that there were two menacing gestures," Stern said at the time.
Speaking broadly, he added, "I guess I would say that the league is sending a message that says you're the best athletes in the world, play the game. OK? And you know what, if you get baited, don't take the bait and let's play . We're not going to let it degenerate into something else, period."
Partly because of that episode, the NFL decided to make the identification of gang signs a point of emphasis this season, and has called on the resources of local and national authorities to learn more about gang culture.
"We were always suspicious that [gang-related hand signals] might be happening," said Mike Pereira, the NFL's vice president of officiating. "But the Paul Pierce thing is what brought it to light. When he was fined that's when we said we need to take a look at it and see if we need to be aware of it."
NFL game officials will not be responsible for identifying gang signals but will alert league headquarters of anything unusual or suspicious they see. League executives declined to outline what action might be taken against offenders, but Pereira said, "it will be dealt with harshly. The commissioner is not going to stand for gang signals on the field."
Ahlerich does not believe the problem to be widespread in the NFL but says the league has spoken to some players about their use of hand signals. He declined to identify the players.
First-year players were counseled on the matter at the recent rookie symposium, and last year a video on the dangers of gangs was required viewing for every player in the league.
The way some players see it, there is guesswork involved, even for the experts who are studying game video.
"Guys come from all over the country, and who knows what they're really doing?" said Jacksonville Jaguars receiver Dennis Northcutt, adding he cannot remember seeing a gang gesture in his nine NFL seasons. "People have got signs for their kids, signs for their fraternities. How do you differentiate who's really throwing up gang signs?"
Northcutt gave an example.
"This is a gang sign," he said, touching his index finger to his thumb to form a squished OK sign. "But at the same time, it's a sign for a personnel group."
Pereira said the gang experts take those factors into account and are very thorough when investigating gestures that appear suspicious. They are on the lookout for "symbols, clothing, jewelry or other items that would signify an association with criminal gang enterprises," Ahlerich said.
That's not unique to the NFL and NBA, nor is it limited to professional sports.
In an e-mail, NHL spokesman Frank Brown said Tuesday his league has "a general prohibition of profane, vulgar or inappropriate gestures (i.e., the throat slash). I am not aware of there ever having been reason to employ a gang expert."
Major League Baseball doesn't study game video, but it does have a policy legislating merchandise. About a year ago, at the insistence of baseball and the New York Yankees, apparel-maker New Era pulled from the shelves Yankees' caps featuring the team's insignia emblazoned with gang colors and logos.
In college sports, the Pacific 10 Conference in 1992 instituted a rule prohibiting football players from wearing bandannas, allowing them to wear elastic skullcaps only if they were in the school's primary colors or black.
Former USC coach Larry Smith was instrumental in the formation of that rule, according to conference spokesman Jim Muldoon, and was acutely aware of gang-related issues.
Former NFL player Marcellus Wiley says he has known players to make gang signs while celebrating big plays, even if they have no direct association with those gangs.
"A lot of guys when they get into the league, they aren't actually throwing up gang signs as if they're still active gang members, or were ever gang members," said Wiley, who grew up in South Los Angeles. "But it's just like Reggie Bush wearing [the area code] 619 under his eyes. It's just kind of to symbolize where you came from."
The irony, Wiley said, is often the athlete flashing the sign was "allowed an opportunity to make it as far as we could without being approached by that lifestyle, that violence, all the stuff that went on in the neighborhood.
"We were given an access pass to get beyond those things. And then we get to the NFL and we want to be tough. We want to get to the NFL or NBA and we want to be hard, get tattoos everywhere, throw up gang signs . And those guys know that. You don't live that lifestyle and graduate out of it.
"Where I'm from," he added, "you're not the one that wants to throw up a gang sign if you're in that neighborhood. Now, in front of millions of people on TV in the middle of the 50-yard line, who's going to attack you? Who's going to do something to you?
"But you do that on Slauson and Crenshaw and see what happens."