Frank is the luckless security guard who mans the front gate at the Regis School. Which means that when Luis Cali and his men decide to let themselves in, they'll have to get past this diligent sentinel.
Not that it proves too difficult.
The terrorists pull up in two vans and are stopped by Frank, and Cali's right-hand man, Jack Thorpe, pulls a silenced pistol on the guard, saying, "We don't wanna hurt anybody. Get in the truck."
Rather than comply, Frank decides to be a hero and goes for his sidearm. Why a guard at a boarding school, even one for rich delinquents, would be given a semi-automatic pistol, is left unanswered, as Jack proves to be the faster gunman. Before Frank can even get his weapon out of its holster, Jack shoots him once in the torso, and down he goes. Frank disposed of, the terrorists' vans proceed onto the campus grounds with no further difficulty.