The weight of the Colorado shooting is heavy for many, and experts say the emotional scars could last for years.
Experts say first comes shock then reality sinks in of what really happened.
"They will re-experience the trauma, the images of it, memories of it, sights, smells and sounds," said John Vincent, a forensic psychologist at the University of Houston.
Dr. Vincent describes what is called Acute Stress Disorder. It is similar to PTSD. Vincent said besides reliving the moments of horror inside that movie theater, many will go into an avoidance mode.
"Many of these people are not going to be comfortable setting foot in a theater, let alone seeing a Batman movie. They may also try to block out memories of the experience trying not to think about it, trying not to talk about it," said Vincent.
There's also what is described as Hyper Vigilance -- people who were there may always be on high alert looking for danger in every situation.
Dr. Vincent said it's not the direct victims who witnessed the violence who may suffer, but also the first responders.
"Many of these people will be emotionally scared for a long time to come and obviously that the impact of an event like this," said Vincent.
The positive side, Dr. Vincent said unlike PTSD, most people will recover in a few months.