Update: 3:50 p.m.
"This is an active ongoing investigation" said State Police Lt. Paul Vance speaking at a press conference that is just concluding.
Vance confirmed the death toll: 20 children, 6 adults, including the shooter, and one adult victim at secondary scene for 27 total.
But in response to multiple questions from press: "There are a lot of things we cannot confirm," Vance said.
He did outline a basic timeline, saying the first call came in at around 9:30 a.m.
"Officers immediately entered the school to search for students, faculty and staff and remove them," he said. "They did search every nook and cranny...Those who were rescued were taken to a staging area."
"It is not a simplistic scene," Vance said. "We will be here through the night and through the weekend. We are not putting a time stamp on this process."
Vance confirmed a secondary crime scene in Connecticut, apparently referring to the investigation in Sandy Hook.
Update: 3:38 p.m.
Patch exclusive: The man identified in media reports Friday as the shooter has told friends that he thinks his developmentally disabled brother may have committed the crime, Patch has learned.
A close friend of Ryan Lanza who would not be identified told Patch that he spoke to Lanza as Lanza made his way home from work to Hoboken. Lanza also took to his Facebook page to rail against CNN naming him as the suspect in the shooting in Newtown, Conn.
“I’m on the bus home now, it wasn’t me,” Lanza wrote.
Lanza’s mother, Nancy, a school teacher, is believed to be among the dead.
Patch was among the media outlets to highlight and link to reports naming Lanza as the alleged shooter. Police haven't yet officially confirmed the identity of the gunman.
Update: 3:18 p.m.
Gov. Dannel Malloy is scheduled to hold a press conference at 3:30 p.m. Friday. Malloy, who met with parents, has received an offer of federal assistance from President Obama.
The gunman apparently went to his family’s Hoboken, NJ home before heading to Newtown, CT where he fatally shot his mother in her kindergarten classroom of Sandy Hook Elementary School, according to NBC.
Citing sources, the Associated Press is reporting the gunman who rampaged through the Sandy Hook Elementary School was armed with four guns including a high-powered rifle and is believed to have shot and killed up to 30 people including 18 children. The death toll could rise.
Investigators have identified the gunman “as a man in his 20s from Connecticut and they are searching his father’s home in New Jersey,” according to WABC Channel 7. The hometown was not immediately identified. According to Connecticut State Police spokesman Lt. Paul Vance said the gunman was found dead inside the school.
Friday afternoon distraught parents continued to wait to be reunited with their children. After meeting with parents of the students, Gov. Dannel Malloy is now at the school. Authorities said much information will not be released until the relatives of the victims are notified.
Channel 7 also is reporting the President Obama has telephone Malloy to express condolences and to offer any federal assistance needed in the investigation of the shooting that was first reported to Newtown Police just before 9:30 a.m. Friday.
A fourth-grade student at Sandy Hook Elementary School said he and his classmates were “locked in a closet in the gym” to escape the gunman. In an interview with Channel 7, the student said, “the police came and …. We ran to the firehouse.”
Update: 1:25 p.m.
Press conference is still at least an hour away, an official just told Patch.
Update: 1:20 p.m.
The community is in "sheer shock." Read our interviews with Newtown residents as they try to make sense of the violence.
Update: 1:00 p.m.
Citing an anonymous official "with knowledge" the Associated Press is reporting 27 people dead including 18 children at Sandy Hook Elementary School.
The shooter is believed to be a single adult and is now dead.
Connecticut Gov. Dannel Malloy is in Newtown and a press conference set for 1 p.m. but hasn't yet begun. Patch is there.
Officials in Newtown say they're trying to reunite parents with their children in the wake of a shocking multiple shooting at an elementary school in the town’s Sandy Hook neighborhood.
First Selectman Pat Llodra told Patch that there is no information being released about the victims of the Sandy Hook Elementary School shooting — only confirming that there was a shooting.
"I'm horrified, saddened and shocked that this happened in Newtown," Llodra said. "Our priorities right now are making sure everyone safe and reuniting parents with their children."
A reverse 911 call went out to all Newtown public school parents, NBC is reporting. Parents are converging all around the school seeking information about their children.
One mother of an 8-year-old girl at the school, Brenda Lebinski, told Patch that her daughter is safe thanks to one teacher's decision to move all kids into a closet when a gunman had entered the building.
Lebinski said that she had spoken to her daughter's teacher as well as a volunteer who was in the school at the time of the shooting, and that a masked gunman had shot adults in the school.
"My daughter's teacher is my hero," Lebinski said. "She locked all the kids in a closet and that saved their lives."
According to Lebinski, the school had been on lockdown but police started leading out children and faculty members by class, and several children had blood on their clothing as they were led out. It isn't clear how many kids are still inside the school. Parents continue to surround the area, seeking news of their children.
Christine Wilford, a parent of a seven-year-old boy at the school, told Patch that her son was out of the school and safe with her husband. A woman standing next to Wilford burst into tears, saying her own son was still inside.
Danbury Hospital has confirmed to TV reporters that three patients have been transported by ambulance.
The Hartford Courant is reporting multiple injured parties, saying a shooter had been in the building’s main office and an individual in one area had “numerous gunshot wounds,” police said.
State police reported shortly after 12 p.m. that officials from the state Medical Examiner's Office were en route to the scene.
At a fire station near the school that's serving as a staging area, a woman was being wheeled on a gurney as a helicopter circled overhead and armed officials from multiple state and federal agencies moved beyond a cordoned-off area swarmed by parents. Dozens of parents could be seen walking to the school as motor vehicle traffic snarled the area of Dickinson Drive.
Marilyn Gudsnuk, 52, of nearby Southbury said she heard 10 to 12 gunshots around 9:40 a.m. Gudsnuk, who attended the elementary school herself as a childhood, said she is taking care of a 91-year-old resident who lives across the street from the school.
"I took off running into the house," she said. "I didn't know what was happening. It was scary."
Asked whether she imagined a shooting could happen at her former school, Gudsnuk said, "Never in a million years."
"I just pray for these people," she said. "The anguish they are goin gthrough. And all because someone's not right in the head."
One man who identified himself as a cable worker and declined to give his name, told Patch that he was up on a utility pole at the time of the shooting. When he heard shots, the man said he thought they it was hunters, but then in a few minutes emergency response vehicles sped beneath his ladder.
Newtown Patch will post more information here as it becomes available.
Claire Moses contributed this report.