MYRTLE BEACH, SC (WMBF) - Chris Swecker, the former assistant director for the FBI's Criminal Investigations Division, called the mass shooting at Pulse in Orlando an, "extraordinarily vicious attack."
"This person was a security guard, so he obviously knew how to use weapons," Swecker said. "And in those 20 minutes, before the full response took place from the local police department, he killed almost 50 people."
Swecker said FBI agents and members of the Joint Terrorism Task Force are working to figure out Omar Mateen's motives.
He classified this attack as international terrorism.
According to Swecker, domestic terrorism is inspired by domestic ideology, while international terrorism is inspired by terrorist organizations overseas, such as ISIS.
He said Mateen seemed to be, at the very least, inspired by ISIS, making this a major case of international terrorism.
"We know ISIS is doing this," Swecker said. "They have a standing call to action for anybody who's paying attention on the internet and following their fatwas and their various statements and their various communications."
If ISIS directly supported the shooting by supplying materials, Swecker said the concern now is other operatives could get that same type of support.
He added the people who have carried out these kinds of mass shootings and attacks in recent years seem to follow a certain pattern. They're angry with their lives, which causes them to embrace radical ideology.
Swecker said some have criminal records and histories of drug use.
"I think that the people in the best position to prevent this sort of thing or blow the whistle early in the process are those that are closest to them," he said. "Their social network, their friends, people they might work with, their families."
He also said a triggering event is common.
"There's some talk about him (Mateen) seeing someone, two men kissing or something like that. His ex-wife basically said that he was bipolar and he was a very mentally disturbed individual," Swecker said. "So we're not quite sure what specifically triggered this, but we know that this follows a pattern."
Mateen was previously the subject of a Homeland Security investigation.
Swecker said the FBI has three different levels of investigations that each require a certain amount of information: threat assessment, preliminary inquiry and full investigation.
Those levels are governed by attorney general guidelines, he said.
Swecker said he doesn't know which level of investigation Omar Mateen was at with the FBI previously, but he thinks it is one of the first two due to the brief nature of the investigation.
While FBI agents investigate a known terrorist, they will talk to that person's phone and email contacts, he said.
Swecker thought Mateen was likely on the fringes talking to people, but not taking any threatening action. So, when FBI agents interviewed him, they concluded he didn't present a danger at that time.
Swecker notes people should not let terrorists affect their daily lives. He said they just need to be alert and report anything suspicious.