The country is searching for answers to why a person would kill and hurt so many in Las Vegas. Understanding is a way to heal and find ways to prevent future suffering.
As the investigation continues, Eyewitness News turned to an expert to gain some insight.
The experts have warned after previous mass violence that someone's threats should be taken seriously, especially those who are abusive to people, pets and property.
"The only thing that has been shown to predict future violence, is previous violence, so if somebody has a history of violence, or making threats about violence, or losing their temper, throwing things," explained Dr. Conrad.
LSU Health Sciences Center Psychiatrist Dr. Erich Conrad says there is still much to learn about the Las Vegas shooter that can't be speculated, but studies of the past give some insight. While Dr. Conrad has never treated the suspect, terms like 'snapped' or had a 'mental breakdown' are unlikely.
"It's probably not that he all of a sudden changed over night. It's something that he had planned out for quite a while," he surmises. "This person most likely had some sort of personality disorder, some antisocial personality disorder."
Reportedly, the shooter's father was psychopathic, which is antisocial behavior with the inability to have remorse and sympathy for others.
"As far as the genetics go, there have been studies that are interesting, where people with like, antisocial personality disorder, which are people who are basically criminals and things like that, and tend to be violent, that does tend to run in families," Dr. Conrad said.
He says genetics, but even more so, environment growing up plays a role. A common theme in killings like this, is that the perpetrator feels he's been the victim of some injustice.
"If you see somebody that has, you know, sudden change in their behavior that's unusual, that would be something to pay attention to," Dr. Conrad said.
The doctor says right now there is no cure for antisocial personality disorders, but therapy may be able to help them lower the chance of acting out the behaviors.