UPDATED: Friday, December 14, 2012 - 7:24pm
Newtown, Connecticut — In one of the deadliest school shootings in U.S. history, a gunman opened fire Friday in a Connecticut elementary school, killing 27 people -- 20 of them children, police said.
The gunman is dead, his body in a classroom, a source with knowledge of the investigation told CNN. A law enforcement identified the suspected shooter as Adam Lanza, who was in his 20s. Police have recovered two weapons from the suspect, a Glock and a Sig Sauer, the source said. It's unclear if police killed the suspect.
National media outlets confused the shooter as Ryan Lanza, Adam's brother, earlier today. Ryan Lanza was taken into custody for general questioning from a home in Hoboken, New Jersey, according to three law enforcement officials. They did not label him a suspect.
A parent who was inside the school at the time of the attack said she heard what sounded like at least 100 rounds being fired. She said she saw two school employees who had died.
It was unclear if there were additional injuries or deaths at Sandy Hook Elementary School, but the suspected gunman was dead, a source with knowledge of the investigation told CNN's Susan Candiotti.
The principal and a school psychologist were killed, according to a parent who was at the school during the incident. The vice principal was shot in the foot or the leg, said the eyewitness, who has a second-grader at the school.
The mother of the suspected school shooter was found dead in her son's residence in Newtown, Connecticut, a law enforcement source with detailed knowledge of the investigation told CNN. CNN had previously identified the mother as Nancy Lanza, a teacher at Sandy Hook Elementary School in Newtown, according to law enforcement sources.
The three weapons found at the scene of Friday's Connecticut elementary school shooting were legally purchased by the suspected gunman's mother, Nancy Lanza, a law enforcement official familiar with the investigation told CNN. A Glock and Sig Sauer were found inside the school with the deceased gunman, while a Bushmaster rifle was found in a car outside the school, the official said.
The suspect in Friday's mass shooting at a Connecticut elementary school was dressed in "black battle fatigues and a military vest," a law enforcement source with detailed knowledge of the investigation told CNN.
The Newtown Bee newspaper said one child had been carried out by a police officer and emergency crews had set up triage facilities, expecting additional patients. The Hartford Courant newspaper said one victim had "numerous gunshot wounds."
Aerial images from CNN affiliate News 12 New Jersey showed police officers armed with rifles following a dog into woods near the school.
Other officers, some in tactical gear, stood around the school with guns drawn, CNN affiliate WFSB reported.
A photograph published by the Newtown Bee showed teachers and police leading students out of the building across a parking lot.
One student, a third-grader, told CNN affiliate WTNH that she was sitting in her classroom when police flooded the area.
"We saw police officers and we heard them on our roof and in our building," the girl said.
Some of the children were crying, and others felt they had a stomach ache, she said.
The girl's father told the station the incident was shocking.
"I was pretty shaken up," he said.
All schools in the city were on lockdown Friday as police assessed the situation, state police spokesman Lt. Paul Vance said.
Students were evacuated to a nearby firehouse, the Danbury News-Times newspaper reported.
The first calls came into police around 9:40 a.m., according to media accounts.
Police scheduled a news conference for 1 p.m. ET.
Newtown is about 60 miles north of New York.