Connecticut Shooting: Interfaith Memorial Service Honors Victims in 'Darkest Days of Our Community'

President Obama met with victims' families before the service.

Dec. 16, 2012— -- Mourners packed the Newtown High School auditorium with a sense of resilience and a vow to never forget the 20 first graders and six adults whose lives were lost in an unthinkable act of violence 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 Visits Newtown

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.

As they entered the auditorium before the ceremony, emergency responders received a standing ovation and hugs for their support after what has undoubtedly been the three most difficult days Newtown has ever faced.

Parents held their children close and kissed them before the ceremony began, a reminder of the fragility of the life lost during the senseless act of violence that shattered the town on Friday.

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 today.

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 slaughtered students in two first-grade classes along with teachers and staff.

CLICK HERE for full coverage of the tragedy at the elementary school.

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 Lanza's arsenal was confirmed today 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, Lanza 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 Lanza'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.

READ: Complete List of Sandy Hook Victims

At a news conference today, Vance warned of misinformation being spread on social media by people posing as law enforcement or the shooter.

"It is important to know, we have discussed with federal authorities these issues are crimes. They will be investigated. ... Prosecution will take place," Vance said at a press conference, adding that all information has been and will continue to come through him.

Post-mortem on Shooter, Mother Complete

The medical examiner's office completed the post mortem today on Lanza and his mother, Nancy, who was shot in the head several times before her son went on his killing spree, officials said.

Adam Lanza died of a single gunshot wound to the head, officials said.

This morning on "This Week," Connecticut Gov. Dan Malloy told George Stephanopoulos that Adam Lanza likely heard first responders and took his own life.

"We surmise that it was during the second classroom episode that he heard responders coming, and apparently at that, decided to take his own life," Malloy added.

As the community mourns and families bear the pain of planning 26 funerals before Christmas, school board members hope to get students back to a familiar routine.

"Well, all the mental health experts we've talked to ... tell us that the best thing we can do is to get back to normal operations as soon as possible," said Bill Hart, a member of the Newtown Board of Education.

"We know some teachers won't be prepared to come back," he said. "We are going to be prepared with substitutes. We've got counseling for all. We're prepared to do whatever we have to do to help all of our community."

The town of Monroe has offered to open Chalk Hill School, which is not currently being used, to Sandy Hill students and staff, the Newton Board of Education said in a statement.

The neighboring community's school is expected to be ready to accomocate students in the next few few days, however an exact schedule has not yet been published.

Hart said officials did not yet know what would become of the building that was turned into a slaughterhouse on Friday.

"I think trying to understand what we are going to do with that is a long process and we're not in any way prepared to make those decisions now," he said.