Orlando gunman posted threats to Facebook before massacre

“You kill innocent women and children by doing us airstrikes.now taste the Islamic state vengeance [sic]”, the Facebook post read.

The gunman behind the worst mass shooting in modern U.S. history referenced the terrorist organization ISIS in a Facebook post moments before the massacre, a source close to the investigation told CBS News.

Officials also said that in May Mateen searched on Facebook for the radicalized couple behind the San Bernardino, California, shooting last December.

The Islamic State militant group has claimed responsibility of the attack, however, the extent of its involvement is still being probed.

Police officers work near the nightclub “Pulse” where the mass shooting that killed at least 50 people including the gunman happened, in Orlando, Florida, the United States, June 15, 2016.

Mateen, who was born in NY, called police before the shooting and swore allegiance to the terrorist group Islamic State, according to the police.

While many, especially on the political right, have been quick to point to Mateen’s ties to terrorism, many members of the LGBT community are considering the shooting as another example of violence toward lesbians, gays, bisexuals and transgender people in the U.S. Still others remain focused on the tragedy as another example of the country’s potential need for stricter gun laws. He also reportedly searched online for a speech by Abu Bakr al-Baghdadi, the leader of ISIS, in the days before the attack.

CBS News’ Paula Reid reported the Federal Bureau of Investigation is characterizing the mass shooting as a hate crime and a terror attack.

Orlando Mayor Buddy Dyer said Mateen drove around the Orlando area Saturday evening, going from one place to another, before he opened fire at the gay nightspot about 2 a.m. Sunday.