Adam Lanza blasted his way into the Sandy Hook Elementary School. He fired a half-dozen thunderous rounds from a semiautomatic rifle to open a hole big enough to step through in one of the school's glass doors.
Once inside, he had to make a choice.
Principal Dawn Hochsprung's office was straight ahead. To the right, 25 or so children were rehearsing a play in the school cafeteria. To his left were the first-grade classrooms.
Lanza turned left.
It was about 9:40 a.m. Friday. In just minutes, Lanza — a withdrawn, emotionally detached 20-year-old who lived with his mother and is said to have played graphically violent computer video games — would kill 26 people in the country's second-largest mass killing. Dead were 20 children, four teachers, the school principal and a school psychologist. Earlier in the morning, Lanza shot and killed his mother, Nancy, perhaps the only person with whom he was socially engaged.
Lanza shot himself as police arrived, sirens wailing.
Late Saturday, an army of police detectives continued to interview members of Lanza's family and others who knew him, searching for answers to innumerable questions — chief among them what could have driven anyone to such violence.
Several sources in law enforcement and elsewhere provided what they said was the most current information on how the events leading to the school shootings unfolded.
On Friday morning, as Lanza turned left, toward the first-grade classrooms, Hochsprung and school psychologist Mary Scherlach, shocked by the sounds of gunfire and shattering glass, bolted into a corridor from a conference room across the hall from the classrooms.
He shot them both with the rifle.
The first classroom that Lanza reached was that of teacher Kaitlin Roig. Alarmed by the gunfire, she had hidden her students in a bathroom and closed her classroom door. For reasons that could not be explained Saturday, Lanza passed by Roig's classroom.
The classroom he chose to enter was substitute teacher Lauren Rousseau's, where he proceeded to systematically shoot everyone inside — the 14 children who investigators believe were huddled and clutching one another in fear, Rousseau and a special education teacher who happened to be in the room. Rousseau was filling in for the regular teacher, who was out on maternity leave. Rousseau had been teaching at the school for six weeks.
"There were 14 coats hanging there and 14 bodies. He killed them all," said a law enforcement officer involved in the case.
Lanza next arrived at teacher Victoria Soto's classroom. Soto is believed to have hidden her 6- and 7-year old students in a classroom closet. When Lanza demanded to know where the children were, Soto tried to divert him to the other end of the school by saying that her students were in the auditorium.
But six of Soto's students tried to flee. Lanza shot them, Soto and another teacher who was in the room. Later, in their search for survivors, police found the remaining seven of Soto's students still hiding in the closet. They told the police what had happened.
The two teacher's aides who were killed were Mary Anne Murphy and Rachel Davino. It was unclear which aide was in which room when they were killed.
The first officer to arrive at the school found Lanza's body near the door of Soto's classroom.
The intense violence lasted about 10 minutes. Lanza fired at least three, 30-round magazines with deadly accuracy. Two of the people he shot survived. All of the victims were shot multiple times.
"I did seven (autopsies) myself with three to 11 wounds apiece," Chief State Medical Examiner Dr. H. Wayne Carver III said Saturday. "Only two were shot at close range. I believe everybody was hit (by bullets) more than once."
Investigators believe that the violence began even earlier that morning in the 4,000-square-foot home on Yogananda Street where Lanza is believed to have lived with his mother. He hasn't spoken since 2010 to his brother, Ryan, or his father, Peter, who has a home in Stamford and another in New Jersey, the sources said.
During a search of Lanza's mother's home, police found her body in her bed. She had been shot twice in the head. Authorities have not determined the time between when Adam Lanza killed his mother and left for Sandy Hook Elementary.
Before entering the home, a law enforcement source said that police used a robotic device to search the structure for explosive devices. None apparently were found.
Lanza occupied two of the home's bedrooms, the source said. He is believed to have slept in and kept his clothing in one, and used the other bedroom to store possessions, including his computer.
Two law enforcement sources said the hard drive had been removed from Lanza's computer and broken in pieces. They said that forensic electronics experts at the FBI will examine the drive in an effort to determine with whom Lanza corresponded electronically and how he otherwise used the device.
One of the sources said that Lanza used the computer to play a violent video game in which life-like characters engage in graphic battle scenes.
Police investigators were still stunned Saturday by the scene they encountered at the school a day earlier, in particular by the seven surviving — but shocked — children hiding silently in the closet in Soto's classroom.
Officers found the children during the initial, rushed search of the building for survivors.
"Finally, they opened that door and there were seven sets of eyes looking at them," a law enforcement officer familiar with the events said Saturday. "She tried to save her class" he said of Victoria Soto.
She was shot not far from her desk, from which she had hung drawings on which her students had written captions such as, "I love my teacher Miss Soto."
Police heard what sounded like a child's moans from where the bodies of the children in Rousseau's classroom had collapsed together. Police had to move several bodies to reach an injured boy, who died en route to Danbury Hospital.
Mary Ann Jacob, a library clerk, had 18 fourth-graders with her in a classroom when the shooting started. They heard it over the school's intercom system.
"The intercom had opened up so we could hear some confusion in the office," Jacob said. "So I called the office because I thought it was a mistake and that they didn't realize the intercom was on. The secretary answered and she said there's shooting. So we yelled 'lockdown' in our room and then ran across the hall and yelled 'lockdown' in the classroom across."
"You could hear the shots. They sounded like popping noises, so we tried to minimize it with the kids," she said. "I don't think until we opened the door and there were 15 state cops with these gigantic guns and federal agents escorting the kids out that they really realized what was going on."
Art teacher Leslie Gunn said she was beginning a class on sculpturing clay with 23 fourth-graders when the shooting began. Her first thought was that the sounds of what turned out to be gunshots were a work crew making repairs to the school roof.
"It got really loud," Gunn said. "It was too loud. Something was bad."
Shaking, she dialed 911 frantically but was unable to get through to the police. Eventually she reached her husband.
"I told him I don't know what is going to happen to us."
A couple of the fourth-grade boys started to cry.
"I told the kids something is wrong and we are just going to have to stay here," Gunn said. "I said I love you. And you are all so brave.''
They remained in the room for about 15 minutes. They heard someone banging on the door to the classroom. When she realized that it was the police, she let them in and spoke to her students
"I told the kids [to] hold each other's hands and not let go," Gunn said.
Courant staff writer Matthew Conyers contributed to this story.Copyright © 2015, The Baltimore Sun