Some people in the crowd believe having an armed sentry outside of church and even assigning well-trained volunteers from the congregation to carry guns on the inside would save lives.

“You can have a security plan big enough to choke a mule, but without the right people, you’re sunk,” church security expert Carl Chinn told the crowd.

Chinn speaks from experience. He helped put a security program in place at New Life Church in Colorado Springs several years before a gunman shot and killed two parishioners in a surprise attack a decade ago. Chinn has collected data dating back to 1999 on more than 1,600 “deadly force incidents” at houses of worship in the U.S, including mosques, synagogues, and Sikh temples.