BAILEY, Colo. -- The man who took six girls hostage at Platte Canyon High School last week had been shot a total of four times, including one self-inflicted gunshot wound, according to autopsy results released Wednesday by state officials.

Lance Clem, spokesman for the Colorado Bureau of Investigation, said Duane R. Morrison, 53, had no drugs or alcohol in his system when he fatally shot 16-year-old Emily Keyes after SWAT officers stormed the classroom he had occupied Sept. 27. She died of a single gunshot wound to the back of her head, Clem said.

Earlier, Park County Sheriff Fred Wegener said Morrison was shot by SWAT officers as he shot himself.

Authorities were awaiting more information from Park County Coroner Sharon Morris to determine whether Morrison died from the self-inflicted gunshot wound or from shots fired by SWAT officers, Clem said.

Clem also said school surveillance tapes showed Morrison's yellow Jeep in the parking lot of the school near Bailey, about 40 miles southwest of Denver, the day before as well as the day of the shooting.

Authorities have said Morrison released four of his hostages before SWAT officers blasted their way into Room 206. He was holding two when he died from gunshot wounds. The second hostage was rescued unharmed.

Students and parents were allowed to return to the school Wednesday for the first time to pick up belongings left behind when the building was evacuated last week. Classes were to resume Thursday.

Several hundred students, parents and Bailey-area residents attended a football game Tuesday, the first organized event since the shooting. The game, which was dedicated to Emily's memory, was originally scheduled Saturday.

After the Platte Canyon Huskies' 35-27 loss to the Colorado Springs Christian School Lions, Emily's father, John Michael Keyes, held up a signed game ball and said over loudspeakers: "Thank you for your thoughts, your prayers, your assistance and your actions.

"I love you guys," he said, using a phrase his daughter had text-messaged to her family in the hours before her death.

Platte Canyon School District Superintendent Jim Walpole said on Tuesday that Room 206, where the shooting took place, will be sealed off for the rest of the school year. He said additional security personnel have been hired, and adult visitors will be required to wear name tags in the school.

Students at Platte Canyon Middle School and Fitzsimmons Middle School returned to school Wednesday to meet with their teachers and pick up possessions.

"It was great to see the students back at school today. Everything went very smoothly. Many parents came with their students. Students and staff were happy to see each other in the school building," said Superintendent Jim Walpole. "It was very positive. There were lots of hugs and lots of smiles."

"Both students and staff are benefiting from the incredible community support we have received," Walpole said.

All students will resume normal class schedule on Friday. Mental health support services will be available for students and staff. "We look forward to seeing our students back in class," Walpole said.

The high school sponsored meet-the-candidates night for Wednesday night was cancelled.

The District has established a new Web site for up-to-date information. That site is plattecanyonschoolsinfo.org.