(NEWTOWN, Conn.) -- Mourners packed the Newtown High School auditorium in Newtown, Conn., on Sunday with a sense of resilience and a vow to never forget the 20 first graders and six adults whose lives were lost in a shooting last Friday at Sandy Hook Elementary School.
"We needed this. We needed to be together, here in this room, in the gymnasium, outside the doors of this school, in living rooms around the world," said Rev. Matt Crebbin, senior minister of the Newtown Congregational Church. "These darkest days of our community shall not be the final word heard from us."
Twenty-six candles rested on stage in front of the presidential podium, a reminder of each of the lives lost.
President Obama, who met with the victims' families privately before the memorial service, tried to console the crowd, speaking as both the president and a parent.
"I come to offer the love and prayers of a nation," the president said. "I am very mindful that mere words cannot match the depths of your sorrow nor can they heal your wounded hearts. I can only hope it helps to know you are not alone ... and that all across this land we have wept with you."
Obama also met with first responders before the memorial service to offer his gratitude for their service.
The evening interfaith service came after a rollercoaster day. Parishioners attending midday mass at St. Rose of Lima Catholic Church received a shock when they were told to evacuate after a church official became aware of a credible threat.
About 1,000 people were gathered inside the church at the time observing one of four memorial services being held there.
Witnesses said police entered the church and told parishioners that a threat had been made against the church and the surrounding area and that everyone had to leave immediately.
More than a dozen state troopers armed with assault rifles entered the church's education center next to the church, but after a short time it was determined that threat was over.
Brian Wallace, director of communications for the Diocese of Bridgeport, said that after the massacre on Friday, he felt the evacuation was a vital precaution to take.
"I don't think any of us could be surprised about anything after what has happened," Wallace said.
Plans for three of the 26 funerals were also announced on Sunday.
Noah Pozner, the first grader whose twin sister survived the massacre, and 6-year-old Jack Pinto, will be laid to rest in separate ceremonies Monday afternoon.
The funeral for Jessica Rekos, 6, will be held on Tuesday at St. Rose of Lima Roman Catholic Church.
While the families grieve, federal and state authorities are working around the clock to answer the question on so many minds: "Why?"
ABC News has learned that investigators have seized computers belonging to Adam Lanza from the home he shared with his mother Nancy, the same place he killed her before going to Sandy Hook Elementary School, where he fatally shot students in two first-grade classes along with teachers and staff.
Authorities are forensically investigating those computers and are also examining devices owned by Ryan Lanza, the gunman's older brother, to see if they can learn anything more about Adam and what caused him to snap.
The magnitude of Adam's arsenal was confirmed on Sunday by Connecticut State Police, who said the 20-year-old had hundreds of rounds and used multiple high capacity magazines when he went on the rampage at the elementary school.
After shooting at victims in two classrooms and a hallway with a high-powered semi-automatic rifle, Adam put a bullet into his own head with a handgun.
"The weapon that was utilized most of the time during this horrific crime was identified as a Bushmaster AR-15 assault weapon," Connecticut State Police Lt. Paul Vance said. "The trajectory of the shots and all of the ammunition used in the horrible crime will be examined."
Vance said three weapons were found at the scene, while a fourth -- a shotgun -- was recovered from Adam's vehicle.
ABC News has learned that both the shooter and his mother spent time at an area gun range, however it was not yet known whether they had shot there.
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