When a corrections officer has a nightmare, it may look like this: a female prison counselor walking down a hallway is silently stalked by an inmate. Through propped open security doors, he follows her into her office. She carries books. He carries an 8-inch shank crafted from a bucket handle. She is 27-year-old anger management therapist. He is a serial rapist serving a 694-year sentence. He takes her hostage, barricades the door to her office, and sexually assaults her.

When it's only a bad dream, the sound of an alarm clock is normally enough to rescue a sleeping CO before things become more gruesome.

But when it actually happened in July 2004, it took Lt. Keith Hoffer and the sound of two gunshots to save the life of counselor Cassie Arnold and rescue the Delaware Correctional Center from its worst nightmare. 

"It was my training that brought me over the wall," said Hoffer, whose actions earned him the North American Association of Wardens and Superintendents Medal of Valor on Aug 8. "But, honestly, I was scared the moment it occurred."

Hoffer, a 25-year veteran in corrections, came through a false ceiling just above the office where inmate Scott Miller was holding Arnold hostage. He shot Miller twice, killing him and ending the ordeal.  

"I don't care who you are, it's a very menacing feeling," said Hoffer.

Normally, Hoffer serves as head of inmate security and transportation at the Kent County, Del. Courthouse. But when a hostage crisis occurs, Hoffer also serves as leader of the Corrections Emergency Response Team (CERT).

"When it happened I was paged and arrived at the scene with the rest of the CERT team," said Hoffer. "They explained the situation to us when we got there."

Miller, a violent sex offender, had followed Arnold into a staff area forbidden to inmates. He gained access to the area through two glass security doors that had been propped open, according to a statement Arnold made shortly after the incident last year.

Miller initially grabbed Arnold and forced her into a bathroom, but she screamed and three officers arrived. Miller put the shank to her neck and threatened to kill her if the officers did not back away. He then forced Arnold out of the bathroom and across the hallway and into her unoccupied office. Once there, Miller locked the office door and barricaded it with five filing cabinets. 

A hostage negotiation team arrived and spoke to Miller though the door. He demanded to speak with his lawyer and wanted to see the warden, according to a report made by the Delaware Attorney General's Office.

After several hours of negotiations, Hoffer said he and the rest of the CERT team discovered that, through an adjacent office, they could access the room where Miller had barricaded himself and Arnold.

By scaling the common wall dividing the offices, Hoffer and his team were able to look down on Miller and Arnold through a false ceiling meant for duct work. After removing a ceiling tile, Hoffer, stood atop filing cabinets and, with the assistance of a teammate, was able to see into Arnold's office. Hoffer, confident he could take action if necessary, then climbed down and waited in the adjacent room.

Hostage negotiators in the hall continued to speak with Miller through the barricaded door until they noticed a strange silence. 

"It became very quite," said Hoffer. "I was suspicious of the quiet so I looked over the wall and saw the tail end of a rape. I did not see the rape but knew she had been assaulted because I saw the nude lower half of her body."

 Apparently incensed that the warden had not agreed to see him, Miller became violent and began sexually assaulting Arnold, according to a statement she made at a press conference.

However, Miller stopped the assault, apparently after he heard a noise from the ceiling, according to Hoffer.

"He jumped up and tried to stab me a number of times," said Hoffer. "When it became clear he wasn't about to get to me, he raised his hand and with the knife, screamed he was going to kill her [Arnold], and ran toward her. I knew he would kill her."

Hoffer, sure that Arnold's life was in danger, used deadly force to save her life.

"I came over the wall [and dropped from the ceiling] and fired once," he said. "He kept moving toward her, so I fired again. We then handcuffed him because we were not certain he was dead."

But both shots had struck Miller directly in the back and he was indeed dead.

"Immediately afterwards we got the counselor to some paramedics and my team members gathered in a crowd around me," said Hoffer. "They say I had the 1,000 mile stare. They were all very supportive. They were there for me."

Now, more than a year has passed since the shooting. Arnold and Hoffer have spoken on several occasions and she has thanked him both privately and publicly for saving her life.

"God bless him," Arnold told reporters last year. "He saved my life and I am so thankful."

When asked how he felt about the incident one year later, Hoffer said, "The counselor [Arnold] and I had a conversation the day after her 28th birthday. She said, 'I turned 28 because of you.'... That's how I feel."