VT cops take the JJ approach

The five minutes police spent breaking into the building proved to be crucial as Cho moved through Norris Hall unimpeded... "If you go in with your backs turned, you're never going back," Geller said. "There's got to be some sort of organization." Some police and security experts question the five-minute delay, saying authorities should have charged straight into the melee. "You don't have time to wait," said Aaron Cohen... "You don't have time to pre-plan a response. Even if you have a few guys, you go."

Nahhh, says JJ. You take your sweet time, make sure the door is broken according to rule X1JTR, and all t's are crossed and i's dotted, before giving the assault, and give the gunman time to snuff out as many lives as he wants. That's the JJ plan.