California Police confirmed Wednesday evening that Syed Farook, 28, and Tashfeen Malik, 27, were the suspects who perpetrated the mass shooting which killed 14 people. The couple were reportedly either engaged or already married. Questions regarding the existence of additional shooters still on the loose were denied by the authorities, who reassured the gathered reporters that any further information would be released in the event of a new threat.Following their getaway, Farook and Malik were later slain in a shootout with police.San Bernardino Police Chief Jarrod Burguan said Farook was a U.S.-born county employee who had attended a holiday party at the Inland Regional Center, a social services agency, and later returned to open fire on the celebration.Burguan said the motive for the shooting remained unclear, and praised the action of the officers who killed the suspects as "heroic." One officer injured in the shootout was evacuated to hospital, and is expected to survive his injuries.Farook was identified earlier on Wednesday by his brother-in-law, who identified as Farhan Khan. Khan said he had no idea what might have motivated the attack, but offered his condolences to the victims. He said his relative was a US citizen."Why would he do that? Why would he do something like this? I have absolutely no idea, I am in shock myself," Khan said at a news conference in Anaheim, California, south of Los Angeles.The massacre differed from most other recent US killing sprees in key ways, including the involvement of multiple people rather than a lone perpetrator. It also comes less than three weeks after the deadly attacks in Paris prompted tighter security at many public venues across the United States.STRING OF SHOOTINGSSo far in 2015, there have been more than 350 shootings in which four or more people were wounded, according to the crowd-sourced website shootingtracker.com, which keeps a running tally of US gun violence.The shooting in California comes less than a week after a gunman killed three people and wounded nine in a shooting rampage at a Planned Parenthood clinic in Colorado Springs, Colorado. In October, a gunman killed nine people at a college in Oregon, and in June, a white gunman killed nine black churchgoers in South Carolina.Gun control advocates, including Democratic President Barack Obama, say easy access to firearms is a major factor in the shooting epidemic, while the National Rifle Association and other pro-gun advocates say the Second Amendment of the US Constitution guarantees Americans the right to bear arms.