When a gunman menaced a small Seattle college, a student pepper-sprayed the attacker, ending his rampage. When an armed couple who had already killed two police officers entered a Las Vegas Wal-Mart, a shopper with a concealed weapon tried to confront them and was killed. And when an Oregon high school student fatally shot a classmate and wounded a teacher, the teacher made his way to an office and alerted officials.

These scenarios, which all unfolded over the past week, demonstrate the risky and potentially life-saving decisions faced by anyone in the path of an active shooter.

Q: At a time when shootings are occurring almost daily, what should people do if confronted with a shooter?

A: Bo Mitchell, president of 911 Consulting, tells his clients that their first goal is to run away. "If you see this happening far enough away from you that you don't have to be part of it, we want you to run," Mitchell said. If that's impossible, he advises hiding in a room and locking the door. Fighting back is a last resort. "You want to act with speed and total surprise, and you want to get a fire extinguisher or a pair of scissors or a chair and go after that guy because you have no other choice."

Q: Has the advice from experts changed?

A: No, Mitchell says. "The threat defines the response. These kinds of threats have been going on for a century or more, but the number of events is going up and that's troubling," he said. In each of the recent cases, victims had to make swift choices about their own safety and protecting the people around them.

Q: Have police changed their response tactics?

A: Before the 1999 shooting at Columbine High School, police response to mass shootings was slower and more deliberate. Patrol officers would often wait for a more heavily armed SWAT team to arrive and clear a building. But with active-shooter situations on the rise, authorities have changed their tactics to respond faster. Now more local officers know how to fan out in teams to quickly eliminate the threat of a gunman, said Thomas Aveni, executive director of the New Hampshire-based Police Policy Studies Council. Paramedics and firefighters are receiving the training, too, "to respond as quickly as possible, rather than wait for additional resources."