Whether it's Devin Kelley killing 26 people in a Texas church or Stephen Paddock gunning down 59 by spraying bullets from a Las Vegas hotel, it's difficult for psychologists to explain why someone would commit a mass murder.
"There is a very understandable tendency, I believe, to try to make sense out of something like this," said Shreveport's Dr. Bruce McCormick.
"Most of the individuals that we've seen, including the one involved in the church shooting just recently, as far as we know now at least, are struggling with their own demons."
On Monday, President Donald Trump called Sunday's shooting "a mental health problem at the highest level."
The vast majority of people with mental illness are not dangerous, and mass shootings like these can contribute to stigmas and make people less likely to get help, McCormick said.
Mental health reform is part of the conversation, he added.
"We are going to have to recognize that mental health issues are under-served and under-addressed and ignored and either deal with it and experience the ill effects or put time money and effort and public recognition into those problems."
McCormick said there is no simple answer or quick fix.
"The answer is being realistic about the multitude of factors that go into mental health needs and finding real-life, real workable programs that can address those issues and then using what funds we have prudently."