shooting(R)Investigators assembled “some very good evidence” to explain what drove a 20-year-old gunman to slaughter 20 children and six adults at an elementary school, police said today, a day after one of the worst mass shootings in US history shattered a small Connecticut town.

The attacker, identified by law enforcement sources as Adam Lanza, opened fire yesterday morning at Sandy Hook Elementary School in Newtown, which teaches children aged 5 to 10. The shooter killed 26 people before turning the gun on himself, and was suspected of killing another person before the massacre.

“Our investigators at the crime scene … did produce some very good evidence in this investigation that our investigators will be able to use in, hopefully, painting the complete picture as to how – and more importantly why – this occurred,” Connecticut State Police Lieutenant Paul Vance told a news conference.

Yale-New Haven Hospital opened a crisis-intervention center in the wealthy suburb of 27,000 people about 80 miles (130 km) from New York City. By mid-morning about 50 cars were parked outside. A sign warned media to stay away.

“If healing can come some day, that’s what I want to ask God to do,” said Andrea Jaeger, who placed a small candle at the makeshift memorial for the victims at the entrance to the school’s driveway on Saturday morning. “Children’s lives were lost and that’s something we all feel.”

The tragedy moved President Barack Obama to tears on national television on Friday and rattled a country that has grown accustomed to mass shootings, but not with victims so young. It also stood to revive a debate about US gun laws.

“The kids who died were in two first-grade classrooms (6-year-olds),” said Mary Ann Jacob, a library clerk who described leading children out of danger during the shooting.

Vance, the police spokesperson, declined to describe the evidence gathered about the shooter’s motives but did say the gunman forced his way into the school, as opposed to being let in.

Crime-scene investigators worked through the night and moved the bodies to the state medical examiner’s office for autopsies, police said in a statement. Victims’ names had yet to be released.

The adult woman found at the secondary crime scene was related to the shooter, a police news release said, and many media outlets have reported it was the shooter’s mother, Nancy Lanza.

Former classmates of the shooter remembered him as a quiet loner – someone who dressed more formally than other students, often wearing khaki pants, button-down shirts and at times, a pocket protector.

Police investigate the guns

Nancy Lanza legally owned a Sig Sauer and a Glock, both handguns of models commonly used by police, and a military-style Bushmaster .223 M4 carbine, according to law enforcement officials who also believe Adam Lanza used at least some of those weapons.

“We’re investigating the history of each and every weapon and we will know every single thing about those weapons,” Vance said.

Nancy Lanza was an avid gun collector who once showed him a “really nice, high-end rifle” that she had purchased, said Dan Holmes, owner of a landscaping business who recently decorated her yard with Christmas garlands and lights. “She said she would often go target shooting with her kids.”

Vance pointedly urged the news media to leave alone the families of the shooting victims and said a police officer had been assigned to each family “to help to maintain that solitude.”

Former classmates of the shooter remembered him as a quiet loner – someone who dressed more formally than other students, often wearing khaki pants, button-down shirts and at times, a pocket protector.

“(His mother) pushed him really hard to be smarter and work harder in school,” said Tim Arnone, 20, who first met Lanza at Sandy Hook.

SABC