The shooting of a security guard Wednesday at the Family Research Council (FRC) has spurred a torrent of heated accusations from both sides of the gay rights debate about claims that the conservative organization is a “hate group.”

The National Organization for Marriage (NOM), one of the nation’s leading opponents of same-sex marriage, told The Hill the shooting was a direct result of the Southern Poverty Law Center’s decision in 2010 to place the FRC on its list of hate groups for its rhetoric on gays.

Brian Brown, the president of NOM, pointed to a recent blog post by the Human Rights Campaign (HRC), one of the largest gay-rights groups in the country. The post, “Paul Ryan Speaking at Hate Group’s Annual Conference,” called attention to the vice presidential candidate’s scheduled appearance at the FRC’s national summit next month.

“Today’s attack is the clearest sign we’ve seen that labeling pro-marriage groups as ‘hateful’ must end,” Brown said in a statement issued following the shooting.

“For too long national gay rights groups have intentionally marginalized and ostracized pro-marriage groups and individuals by labeling them as ‘hateful’ and ‘bigoted.’”