Investigators are now piecing together information to find out more about the Las Vegas shooter.

Kenneth Gray, a retired FBI agent who now works at the University of New Haven, says investigators will gather all of the information and evidence surrounding the case to try and figure out who Stephen Paddock was and what his motive was.

According to his brother, Paddock was retired, a high-stakes gambler and did not have any political or religious affiliations. Gray says this makes it harder to pinpoint the exact reason behind the massacre. He does add that there are warning signs for people to look out for.

"If you see somebody that is stockpiling weapons," Gray says. "All of a sudden their personality changes drastically and they seem to be extremely angry and extremely aggressive, that would be something to call law enforcement to: Simply, this person is acting different, this person may be a threat."

Gray says that although the motive is still unclear, one thing is certain -- this massacre was planned.

The former FBI agent says each mass shooting is unique, but they have something in common -- weapons. Gray says access to these high-capacity weapons is what turns a bad shooting into a worse one.