While the scene of the-- which claimed the lives of at least 59 people and wounded more than 500 others during a country music festival on the Las Vegas Strip -- was surely terrifying, experts say it is too early to know whether the attack meets the definition of an act of terrorism.
The gunman was identified by police as 64-year-old Stephen Craig Paddock of Mesquite, Nevada.
"We believe it's a solo actor. A lone wolf," said Clark County Sheriff Joseph Lombardo.
Two law enforcement sources told CBS News that there does not appear to be a connection to terrorism at this time, and FBI Special Agent in Charge Aaron Rouse confirmed at a news conference Monday that Paddock had no known connection to any international terrorist group.
However, "It's really too early to rule anything like that out," said CBS News justice and homeland security correspondent Jeff Pegues.
Investigators are busy digging into Paddock's past and potential contacts to understand what may have motivated his actions.
online claiming that the gunman had recently converted to Islam and was acting on behalf of the group, but it offered no evidence. Terrorism experts noted that the group has made false claims in the wake of other incidents in the past.
Of course, association with a known terrorist group is not required for an attack to be considered terrorism, but the attacker's motivation is a key piece of the puzzle. An attack driven by, for example, personal grievance or financial gain, or as a result of profound mental illness, would not generally meet the definition of terrorism.
The Oxford English Dictionary defines terrorism as "the unlawful use of violence and intimidation, especially against civilians, in the pursuit of political aims."
CBS News justice reporter Paula Reid explains U.S. terrorism laws have evolved significantly since the Sept. 11 terror attacks to emphasize foreign terrorism ties.
Domestic terrorism, according to U.S. federal code posted online by Cornell Law School, is defined as: "Activities that involve acts dangerous to human life that are a violation of the criminal laws of the U.S. or of any state" that "appear to be intended to intimidate or coerce a civilian population; to influence the policy of a government by intimidation or coercion; or affect the conduct of a government by mass destruction, assassination or kidnapping; and occur primarily within the territorial jurisdiction of the U.S."
The intent to affect government policy is necessary for a case to meet the legal definition as terrorism.
If the investigation reveals that Paddock had a domestic political motivation, the incident could be described as domestic terrorism, Reid reported. But the case could never be charged as such since Paddock died at the scene and will never face criminal prosecution.