The scene at the Amish schoolhouse was so horrific, the deputy coroner says she hopes "never to see anything like it again."

Ten girls had been shot, five fatally, and the gunman was dead.

"It was horrible. I don't know how else to explain it," Amanda Shelley, deputy Lancaster County coroner, told the Associated Press Wednesday.

"I hope to never see anything like that again in my life."

The gunman -- 32-year-old milk truck driver Charles Roberts -- was wearing jeans, a T-shirt and a button-down shirt, Shelley said.

Roberts, a father-of-three, "really appeared he had planned on staying there a few hours," Shelley added.

Possible sexual assaults planned

Items found at the one-room West Nickel Mines Amish school led authorities to believe that Roberts may have had a plan that went beyond the execution-style slayings of the five girls.

Police say Roberts may have been planning to sexually assault almost a dozen of the girls based on the items he brought to the schoolhouse, including flexible plastic ties, eyebolts, and lubricating jelly.

"It's very possible that he intended to victimize these children in many ways," said Pennsylvania State Police Commissioner Jeffrey Miller.

Using a checklist that was later found in his pickup truck, Roberts brought to the school three guns, a stun gun, two knives, a pile of wood for barricading the doors, a bag with 600 rounds of ammunition, a change of clothes and toilet paper.

However, his siege quickly became shorter than he expected after Roberts became "disorganized'' when police arrived, Miller said.

As authorities swarmed, Roberts opened fire on 10 tied-up little girls, fatally wounding five, before killing himself.

The dead and wounded girls ranged in age from six to 13.

During the standoff, Roberts told his wife in a cellphone call that he molested two female relatives 20 years ago when they were three to five years old.

However, "it's unknown what type of molestation, whether it was fondling or inappropriate touching, or sexual assault, or if anything occurred, we don't know," said Miller.

Police say they are hoping to interview the two relatives who may have been molested by the gunman, but at this stage Roberts' claim has not been confirmed.

Family members told police they knew nothing of molestation in his past.

Police say Roberts started buying supplies for the deadly siege six days before storming the schoolhouse.

Tormented

Miller said he left separate notes at home for his wife and each of his three children, who are all six years or younger.

In the note to his wife, Roberts said he had been tormented by dreams about molesting again and was haunted by the death of his daughter, born prematurely in 1997.

The baby, Elise, died 20 minutes after being delivered, Miller said.

Elise's death "changed my life forever," the gunman wrote to his wife.

"I haven't been the same since it affected me in a way I never felt possible. I am filled with so much hate, hate toward myself hate towards God and unimaginable emptyness (sic) it seems like everytime we do something fun I think about how Elise wasn't here to share it with us and I go right back to anger."

Forensic psychiatrist Dr. John Bradford told CTV's Canada AM it is difficult to say whether Roberts had been troubled for much of his life or if his breakdown was recent.

"(The) easy answer is we don't know. However ... it seems as though there was a change in Mr. Roberts. He became less of a happy-go-lucky person and obviously we know there was a week when he was planning this," Bradford said.

"If his mood deteriorated and he became psychotically depressed -- even though these (past events) may be relatively minor incidents that he should have got over, they would take on a new emphasis and could become part of the driving force to commit this mass homicide."

Prayer services

At least three prayer services were held Tuesday night, attracting more than 1,600 people, who observed moments of silence, sang mournful hymns and listened to Bible readings.

"Set your troubled hearts to rest," the Rev. Douglas Hileman said from the pulpit of Georgetown United Methodist Church, a short distance from the crime scene.

"May we be able to forgive as God has already forgiven us."

Funerals for four of the girls are to be held on Thursday, while the fifth girl will be buried Friday.

Three of the wounded girls were in critical condition Wednesday and two were in serious condition.