If you're headed to the movies this weekend you may be thinking of the victims of this morning's mass shooting in Aurora, Colorado, and wondering whether it could happen here.
"This wasn't something that this individual thought of last night or the night before. It appeared to have been well thought out, carefully crafted, he timed the scene in the movie," says expert crime analyst Ken Jefferson.
Jefferson says he thinks theaters will start trying to provide security for customers.
"In light of this I'm certain that the movie theaters will try and provide some type of security or protection for the patrons that will be coming and going," Jefferson.
He says if you ever find yourself in a situation like that, with a gunman in a confined space, take cover immediately and try to call 911. Jefferson warns not to stay on the line for too long or talk too loudly, so as not to draw the shooter's attention.
At least a dozen people were killed early Friday morning when 24-year-old James Holmes opened fire on a movie theater filled with patrons seeing the midnight premiere of "The Dark Knight Rises."