The booklet includes guidance similar to what's used by university and business security forces across the country.
"The book has been a good reference guide" for security plans, said Captain Ashly Foster of the emergency operations unit at Mall of America in Bloomington, Minn.
Shooting incidents unfold over a matter of minutes, and semiautomatic weapons rack up casualties quickly.
With so little time for police to react, it's up to the intended victims to try to avoid the carnage as much as possible until help arrives, said Paul Browne, a spokesman for the New York Police Department.
The Department of Homeland Security's guidance, first compiled in a 2008 booklet aimed at retailers and mall operators, has proved so popular it's being used by companies throughout the private sector, said Peter Boogaard, a department spokesman.
Since the "Active Shooter Program" began four years ago, 125,000 people in the government and private sector have been trained in the seminars, online course, booklets and other guides it offers, according to Boogaard.
Boiled down to the essentials, the advice is to evacuate or hide, and if those options aren't available, disrupt the attack by distracting the shooter or taking him out.
Goddard said he and other students in his French class had no opportunity to do anything other than hide under their desks as the rampage unfolded on Virginia Tech's Blacksburg campus before bullets started flying through the door and Cho entered, spraying the room with gunfire, Goddard said.
It wasn't until Goddard said he smelled gunpowder and felt the warmth of blood spreading over his newly broken leg that he knew what was happening.
"I really totally didn't understand what was going on until I was shot the first time," said Goddard, who now is an assistant director at the Washington-based Brady Center to Prevent Gun Violence, which advocates for gun control.