WASHINGTON (AP) — Civil rights groups in Washington, D.C. are holding a vigil for three Muslim students killed in a dispute over parking spaces in the college town of Chapel Hill, North Carolina.

Police are still trying to determine whether religious hatred played any role in the Tuesday shootings. Craig Stephen Hicks, who’s charged with murder in the killings, has described himself as a “gun toting” atheist.

The father of two of the victims says he’s convinced it was a hate crime.

The civil rights groups holding the vigil in the District include the Council on American Islamic Relations, the nation’s largest Muslim civil rights and advocacy organization, and the D.C. Ferguson movement.

The vigil will begin at 6:30 p.m. Thursday in DuPont Circle in northwest Washington.

Demonstrators will use the hashtag #DC4ChapelHill.