Since the massacre at Sandy Hook Elementary School on December 14, 2012, there have been 74 school shootings.
"'Can you tell us why?'" David Gomez said. "And as a profiler I was taught not to concentrate on the 'why' but to concentrate on the 'how.'"
As a former FBI criminal profiler, Gomez believes, "how?" is the better question, since motivation differs from case to case.
"Because you need to focus on what you can do as opposed to what you want to know," he said.
The shock has turned toward outrage.
On social media, the Twitter hashtag trending is #notonemore, along with comments like, "My 9 year old just said he's glad its summer because no more kids will be killed at school."
"It's not a recipe for what makes a killer," said Seattle Central College Professor Dr. Krystle Balhan.
Dr. Balhan believes the conversation around gender is missing, as most of the high profile cases involve men.
Even so, the details of each incident vary.
If there is one common denominator, Dr. Balhan says, it's mental illness.
"Violence is not inevitable. That is not our destiny," Dr. Balhan said.
Since the shooting at Columbine High School, the first case to highly publicize delusional and psychotic fantasy, mental illness has become the focus of debates about how to stop the violence.
"Granted, we live in a free society. You can't force these people to take their medications. That, I think, is the big problem," Gomez said.
Gomez calls that a policy issue, which may gain new insight from fields that are now working together like law enforcement, psychologists and criminologists.
"Different disciplines that can come at really complex problems from different angles, and I think that's probably the solution," Dr. Balhan said.