Namee Barakat embraces his wife Layla Barakat, parents of shooting victim Deah Shaddy Barakat, during a vigil on the campus of the University of North Carolina in Chapel Hill, North Carolina February 11, 2015. Gunman Stephen Hicks, who had posted anti-religious messages on Facebook and quarreled with neighbors, was charged with killing three young Muslims in what police said on Wednesday was a dispute over parking and possibly a hate crime. The victims were newlyweds Deah Shaddy Barakat, 23, a University of North Carolina dental student, and his wife Yusor Mohammad, 21, and Yusor's sister, Razan Mohammad Abu-Salha, 19. [Photo/Agencies]

The slayings of three young Muslims near the University of North Carolina tapped a deep well of fear and anger over bias toward American Muslims.

Many Muslims were angered that the killings Tuesday night were slow to draw public attention. The hashtag (hash)MuslimLivesMatter was used widely on Twitter as word spread Wednesday morning that the three homicide victims were Muslim.

When police said a preliminary investigation indicated a parking dispute had triggered the shootings, several US Muslim leaders said the brutal nature of the crime warranted a hate crime investigation from both federal and local law enforcement. The family of the victims joined the call for a hate-crime inquiry.

Dalia Mogahed, director of the Institute for Social Policy and Understanding, a think-tank that specializes in Muslim issues, said she was disturbed that the media lagged in picking up on the religious significance of the fatal shootings.

"How would we be dealing with this issue if the faith and ethnicity of the victims and perpetrator were switched, if a brown-skinned person went into the room of three white people and shot them?" Mogahed said. "We're all just floored by the blatant double standard that we're seeing in both law enforcement and media coverage of the issue."

The victims were a newlywed couple, Deah Shaddy Barakat, 23, and Yusor Mohammad, 21, and Mohammad's sister, 19-year-old Razan Mohammad Abu-Salha. Craig Stephen Hicks, 46, was charged with three counts of first-degree murder in the shootings.

The father of the women, Mohammad Abu-Salha, told The News & Observer of Raleigh that Hicks had harassed his daughter and husband a couple of times before, and had a gun in his belt when he spoke with them. Abu-Salha said his daughter Yusor, who lived next door to Hicks, wore a Muslim head scarf and told her family a week ago that she had "a hateful neighbor."

"Honest to God, she said, 'He hates us for what we are and how we look,"' he told the newspaper.

Muslim Advocates, a civil rights organization based in California, urged US Attorney General Eric Holder to open a federal inquiry into the homicides. "We cannot ignore the environment in which this incident took place," said Madihha Ahussain of Muslim Advocates.

The Council on American-Islamic Relations made a similar plea. Chapel Hill police Chief Chris Blue said, "We understand the concerns about the possibility that this was hate-motivated, and we will exhaust every lead to determine if that is the case."

Muslim groups held vigils for the victims in North Carolina, New York, Virginia and elsewhere, while others organized a worldwide Quran reading as a memorial.

The reaction reflects the alarm many American Muslims feel in the face of anti-Muslim prejudice which has persisted since the Sept. 11 terror attacks, often spiking after terror attacks overseas.