So many tragedies have shocked America these past few months that the search for answers to the simple question "why?" has become a national obsession. And as the country's weapons culture undergoes international scrutiny, the National Rifle Association is not alone in finding itself caught in the uncomfortable spotlight.
In a sporting sense, new year is usually all about the run-up to Super Bowl. The drum rolls have already begun but for many in American Football the need remains to look back to the double shooting involving Kansas City Chiefs linebacker Jovan Belcher.
On the morning of December 1 Belcher shot the mother of his three-month-old daughter 10 times with a .40mm handgun before driving to the Chiefs' training ground and firing a bullet into his right temple in front of the general manager and coach.
His actions have placed the NFL's relationship with guns in the spotlight and raised uncomfortable questions about a link between off-field violence and on-field concussion.
Bob Costas, an NBC presenter, even discussed gun control during a broadcast of Sunday Night Football the day after Belcher's death. Since 1996, the league has a weapons policy prohibiting players from carrying guns at work. The Belcher incident reportedly led to more than half-a-dozen NFL players surrendering their firearms to league security officers. An estimated 45-50 per cent of adult Americans own guns; the proportion of NFL players with weapons is believed to be far higher.
Tony Dungy, the former Indianapolis Colts coach, told a radio show: "Every year, the first day of training camp, I'd say, 'How many of you have a gun?' Three-quarters of the hands would go up every year. It's, 'Coach, you're living in another world. I've had a gun since I was X years old. I'm going to keep a gun. I'm always going to have a gun to protect my family'."
Easy access to guns is especially ominous since a significant minority of players appear to develop mental problems stemming from their violent jobs. It is not certain that the after-effects of concussions was a factor in Belcher's actions, but the erratic behaviour of a number of NFL alumni and analysis of the brains of dozens of dead players has made the connection between hard hits and sick minds impossible to refute. Four retired and three active NFL players have committed suicide since 2010, all from self-inflicted gunshots.
Dave Duerson, an 11-year NFL veteran and two-time Super Bowl winner, became a successful businessman after he hung up his helmet in 1993. According to his family, a dozen years later he started acting aggressively and making poor decisions. He shot himself dead in 2011 and left a note asking for a post-mortem on his brain, which confirmed serious damage.
Even baseball has become drawn into the debate after the former hitter Ryan Freel took his own life last month. The 36-year-old had psychological problems. He suffered around a dozen concussions during his career and his family have agreed to let researchers examine his brain.
Some 4,000 former NFL players are suing the league for alleged fraud and negligence, mostly via a consolidated lawsuit that will be heard in a Philadelphia court this year. The players argue that for decades the NFL concealed a link between concussions and long-term brain diseases such as dementia and "punch-drunk syndrome".
With billions of dollars at stake, these days the league has an enlightened approach towards player safety, but some find it impossible to stay out of trouble.
Data shows that police made 43 arrests involving NFL players in 2012 – below the average of 52 per year since 2000. Ten were drug-related and eight for alleged violence. Eighteen were for drink-driving.
A week after the Belcher tragedy, Jerry Brown of the Dallas Cowboys died in a car crash in Texas. Brown was a passenger in a Mercedes driven by a team-mate, Josh Brent, who is facing a drink-driving charge.
Ted Johnson is a three-time Super Bowl winner with the New England Patriots who quit in 2005 after suffering concussion-related illnesses. Now a broadcaster, he became depressed and addicted to drugs after retiring and believes that his head injuries have impacted on his ability to cope with stress. He believes problems are inevitable given the game's bloodthirsty nature.
"A lot of guys who play football don't come from stable, nurturing, healthy homes," he said. "What fuels a lot of guys is anger. The game is inherently violent so you have to be a violent person, particularly on defence. It is brutal."
Among Belcher's last words were reportedly: "I need help! I wasn't able to get enough help." Last year, the league introduced NFL Life Line, a confidential support phoneline, but Johnson doubts that counselling schemes are effective.
"A lot of guys don't have coping mechanisms. In the NFL, it's go get drunk, go get stoned, go find some women, go buy a car.
"I used to get laughed at when I said, 'Why doesn't every team have its own therapist?' They don't want that. The fans don't really care and I don't know if the NFL does because the bottom line is that people still show up for games, buy merchandise, watch on TV. I don't know what would ever derail this train."
The dangerous relationship between guns and the NFL
Gun violence has directly affected dozens of American football stars, both as victims and perpetrators.
Steve McNair, a retired former NFL MVP, was shot dead in 2009 at his Nashville home by his girlfriend, who had bought the gun in a car park for $100 from a convicted criminal.
Washington Redskins player Sean Taylor died aged 24 in 2007 when robbers broke into his bedroom in Miami and shot him.
Darrent Williams, a 24-year-old with the Denver Broncos, was killed while in a limo in 2008 in a drive-by shooting in downtown Denver.
That year, Plaxico Burress, then with the New York Giants, accidentally shot himself in the thigh with his pistol in a Manhattan nightclub. His replacement on the team, Taye Biddle, was shot twice outside his mother's house in Alabama in 2009.
In 1999, 25-year-old Carolina Panthers player Rae Carruth hired hitmen to shoot the eight-month pregnant mother of his unborn child in order to avoid paying child support.