The Investigative Project on Terrorism condemns the massacre of Muslims in two New Zealand mosques during Friday prayer by a self-described "ordinary white man" who "decided to take a stand."

At this moment, 49 people are dead and dozens more are hospitalized in Christchurch.

Three men and a woman reportedly are in police custody, although the killing appears to be the work of one man, described as being in his late 20s. He live-streamed his slaughter and posted an anti-immigrant manifesto online, including on a platform known for extreme right wing ideas.

In it, he said he was inspired by Norwegian mass murderer Anders Breivik and decried a "large group of invaders" who "seek to occupy my peoples (sic) lands and ethnically replace my own people."

The point of monitoring and investigating extremist ideology is to not only limit, but prevent people driven to claim innocent lives based upon their identities, ideologies and faiths. That is true in Jerusalem, in Pittsburgh, in Charleston, S.C., in San Bernardino, and now in Christchurch.

We mourn for those lives lost Friday while gathering for prayer.