NEWTOWN, Conn. – All of the victims killed in the Connecticut elementary school shooting died from multiple wounds from a “long gun” rifle and are classified as homicides, the state’s chief medical examiner said Saturday.

At a news conference, Dr. H. Wayne Carver II described the postmortems on the 20 children and six adults killed in Friday’s attack at Sandy Hook Elementary School.

“I’ve been at this for a third of a century and my sensibilities may not be the average man’s, but this is probably the worst I have seen or the worst that I know of any my colleagues having seen,” he said.

Officials distributed to reporters the names of all 26 victims and were preparing to release the bodies to the families for burial.

Carver said he believed the postmortems of all the children had been completed and those of the adults killed at the school would be done by Saturday night. The postmortems of the assailant and his mother will be done Sunday, he said.

President Obama, meanwhile, planned to attend an interfaith memorial service Sunday in Newtown, the fourth time he has traveled to a stricken city after a mass shooting.

Officials have yet to formally name the shooter, but law enforcement sources have identified him as Adam Lanza, 20, who lived with his mother, Nancy.

Nancy Lanza was the first person killed Friday, shot “in the face or head,” according to law enforcement sources, inside the home she shared with her son.

The Associated Press reported Saturday that police shed no light on what triggered the second-deadliest school shooting in U.S. history, though state police Lt. Paul Vance said investigators had found “very good evidence … that our investigators will be able to use in painting the complete picture, the how and, more importantly, the why.” He would not elaborate.

However, another law enforcement official, speaking on condition of anonymity, said investigators have found no note or manifesto from Lanza of the sort they have come to expect after murderous rampages such as the Virginia Tech bloodbath in 2007 that left 33 people dead.

The mystery deepened as Newtown education officials said they had found no link between Lanza’s mother and the school, contrary to news reports that said she was a teacher there. Investigators said they believe Adam Lanza attended Sandy Hook Elementary many years ago, but they had no explanation for why he went there on Friday.

According to the AP, James Champion, Nancy Lanza’s brother and a retired police captain in Kingston, N.H., said through the police chief that he had not seen his nephew in eight years. Champion, who still works as a part-time officer, said he would not discuss what might have triggered the rampage since the case is under investigation.

After killing his mother, Adam Lanza then took her car and drove to the school where he forced his way into the building and opened fire, authorities said. He used weapons that were registered to his mother or father, who are divorced, the same law enforcement sources said.

State Police spokesman Lt. J. Paul Vance told reporters that the weapons taken from the house were all recovered at the scene, where Lanza took his own life to become the 28th body during the deadly rampage.

Other law enforcement sources have identified the guns as a Bushmaster .223 rifle, a Glock 9-millimeter pistol and a Sig Sauer semiautomatic. It was unclear Saturday whether the Bushmaster was the “long gun” cited by Carver as the primary weapon in the attack. Law enforcement sources said the Bushmaster was recovered in the car, but Vance denied that assertion at a news conference.

Vance also denied some media reports that the gunman was involved in an altercation with school employees in the days preceding the shooting.

“We’re doing everything we need to do to literally peel back the onion, layer by layer,” Vance told reporters, cautioning that the investigation was ongoing.

Although many details of the shooting remained unclear, the effect on this western Connecticut town was deep and painful. From the moment the first shots rang out in the school Friday morning, shock smothered the town, followed by sadness and mourning. Memorial services began Friday, continued Saturday and will probably go on for days as funerals are held.

“Our wound is deep because we are a close-knit community,” Patricia Llodra, the town’s first selectman, told reporters. “We truly care for each other.

“We are coming together with love and support for those families that have suffered this terrible loss. We are a strong and caring place. We will put our arms around those families and around each other. We will find a way to heal so that all our residents, young and old, will again find peace,” she said.

The AP said signs around town read, “Hug a teacher today,” “Please pray for Newtown” and “Love will get us through.”

“People in my neighborhood are feeling guilty about it being Christmas. They are taking down decorations,” said Jeannie Pasacreta, a psychologist who was advising parents struggling with how to talk to their children.

The official list of the dead identifies the victims as ranging from in age from 6 to 56 years old. Carver said he believed all of the children were first-graders.

“Everybody was hit more than once,” some from close range, Carver said. “This is a very devastating set of injuries.”

Two of the dead adults had been named earlier and include the school’s principal and another staff member who rushed the gunman as he forced his way into the building, Newtown Public School District Superintendent Janet Robinson told reporters Saturday.

The principal, Dawn Hochsprung, 47, was running at the gunman to protect her students when she was shot, Robinson said. School psychologist Mary Sherlach, 56, also was trying to stop the gunman when she was killed, the superintendent said.

Nancy Lanza had never been a teacher or a substitute teacher at the school, as had been reported, Robinson said. Lanza’s connection to the school, if any, remained unclear.

The shootings in Connecticut — the deadliest toll since the Virginia Tech massacre in 2007 — has stirred the nation and the world, prompting an outpouring of condolences, especially for the youngest victims.

In addition to the formal memorials, impromptu banners and ad hoc signs have sprung up in the town, each carrying pain-filled messages of love and sympathy. Social media, including Facebook and Twitter, have been a constant display of the world’s grief.

One of Meg Fiscella’s friends lost a granddaughter in the shooting. Fiscella said she would miss seeing the little girl’s hair held in place by a big bow every Sunday at St. Rose’s, one of the churches where memorials have been held.

On Saturday morning, Fiscella was walking her two dogs when she saw a man enter the local funeral home. His eyes were red and puffy. In his hand was a pressed little white dress.

“We are devastated. This town will be thought of as another Columbine,” she said, referring to the 1999 killings at Columbine High School in Littleton, Colo. “It is a wonderful little town.”

Many holiday parties were canceled around Newtown this weekend. “No one feels like celebrating,” she said.

On Friday, Connecticut Gov.Dannel P. Malloy told his state that “evil visited this community” and urged healing.

In brief comments Saturday, he called on the state to use love to renew itself in the wake of hate.

“We can hug someone we love a little tighter,” he said.