Police vehicles line the street around a vehicle in which two suspects were shot following a mass shooting in San Bernardino, California Dec. 2, 2015. Reuters

Is the suspect black or white? Is the suspect Muslim or Christian? These are the questions Americans have immediately asked after recent mass killings, underscoring the racial and religious tensions that have simmered across the nation amid debates over national security, gun control laws and discrimination against minorities.

After media reports identified a suspect in a mass shooting in San Bernardino, California, Wednesday as Syed Farook or Sayeed Farook, some reporters questioned whether his faith should be an issue. During a press conference Wednesday night, local law enforcement and FBI officials declined to answer questions about the suspect's race or religion. But conservative leaders claimed Farook was religious and some Muslims lamented that their community could be blamed for the mass shooting.

“We condemn this horrific and revolting attack and offer our heartfelt condolences to the families and loved ones of all those killed or injured,” said Hussam Ayloush, executive director of the Council on American-Islamic Relations in Los Angeles. “The Muslim community stands shoulder to shoulder with our fellow Americans in repudiating any twisted mindset that would claim to justify such sickening acts of violence.”

After attacks in Paris last month by Muslim terrorists and a mass shooting in South Carolina by a white man earlier this year, a debate over how the media treats suspect of color has focused on whether non-white and non-Christian suspects are too often called terrorists compared with white suspects. "U.S. media outlets practice a different policy when covering crimes involving African Americans or Muslims. As suspects, they are quickly characterized as terrorists and thugs (if not always explicitly using the terms), motivated purely by evil intent instead of external injustices," Anthea Butler, an associate professor of religion and Africana studies at the University of Pennsylvania, wrote in the Washington Post in June after the South Carolina shooting.

Media experts have found that Arabs and Muslims have been portrayed by Western media as "typically stereotypical and negative." One report commissioned this year by the Kuwaiti government and based on a surveys and interviews with media experts concluded: "In the past 30 years of thousands of TV show series, there have been less than 10 characters who have been Arab-Americans."

During previous mass killings, Americans have linked race and religon to potential motives, such as when a German pilot downed a Germanwings flight into the French Alps in March. At the time, French prosecutor Brice Robin of Marseille was asked about Andreas Lubitz’s religion by reporters. Robin said he did not know and added, “I don’t think that’s where the answer to this lies.”

After the Paris killings in November, some Muslims expressed fear over a potential backlash. “When this horrific thing happened on Friday, all the Muslims I know went through the same thing,” Ronald Abdul Rahim Hubbs, a member of the Ahmadiyya Muslim Community, one of the oldest Muslim organizations in the U.S., told International Business Times at the time. “You first have the emotions of, ‘Oh my God, that’s terrible.’ The second feeling that comes up is, ‘Here we go again.’”