Police: Gunman forced way in

NEW: Authorities find 3 guns next to Lanza's body and another 3 elsewhere NEW: A law enforcement source says Lanza may have tried to buy a gun this week Authorities identify all of the victims Detectives find "very good evidence" at the school and suspect's mother's house

Watch CNN's LIVE TV coverage of the Connecticut elementary school shooting as the story continues to unfold.

Newtown, Connecticut (CNN) -- Major crime investigators from the Connecticut state police on Saturday were combing "every crack and crevice" of Sandy Hook Elementary School in Newtown, a day after a gunman shot dead 20 students and six adults before apparently killing himself.

Authorities have now identified all of those killed in Friday's tragedy, but they are not releasing a formal list of names and birthdates until the state medical examiner has completed his work, said Lt. J. Paul Vance, a state police spokesman.

The investigators are looking inside and outside the school building and at every car in the parking lot, in what Vance called a "long and painstaking process" that will not be completed for at least another day or two.

Timeline: School violence in U.S.

Law enforcement officials identified the shooter as 20-year-old Adam Lanza, who grew up in the tight-knit community of 27,000. Police say Lanza killed his mother, Nancy, at her Newtown home before going to the school, where he primarily targeted two classrooms of kindergartners and first-graders.

Lanza's motive was unclear Saturday, though Vance said detectives are collecting some "very good evidence" at both the school and his mother's house. He would not say what the evidence includes.

"The detectives will certainly analyze everything and put a complete picture together of the evidence that they did obtain, and we're hopeful -- we're hopeful -- that it will paint a complete picture as to how and why this entire unfortunate incidence occurred," Vance told a packed crowd of journalists at a Saturday morning news conference.

Lanza forced his way into the school, Vance revealed Saturday, though he wouldn't say how or whether Lanza used weapons to do it.

It's also not clear whether Lanza entered before or after 9:30 a.m., the time each day when the school would lock its doors as part of a security system introduced this year. Authorities say the first emergency call about the shooting came in at "approximately" 9:30 a.m. Friday.

.cnnArticleGalleryNav{border:1px solid #000;cursor:pointer;float:left;height:25px;text-align:center;width:25px} .cnnArticleGalleryNavOn{background-color:#C03;border:1px solid #000;float:left;height:25px;text-align:center;width:20px} .cnnArticleGalleryNavDisabled{background-color:#222;border:1px solid #000;color:#666;float:left;height:25px;text-align:center;width:25px} .cnnArticleExpandableTarget{background-color:#000;display:none;position:absolute} .cnnArticlePhotoContainer{height:122px;width:214px} .cnnArticleBoxImage{cursor:pointer;height:122px;padding-top:0;width:214px} .cnnArticleGalleryCaptionControl{background-color:#000;color:#FFF} .cnnArticleGalleryCaptionControlText{cursor:pointer;float:right;font-size:10px;padding:3px 10px 3px 3px} .cnnArticleGalleryPhotoContainer cite{background:none repeat scroll 0 0 #000;bottom:48px;color:#FFF;height:auto;left:420px;opacity:.7;position:absolute;width:200px;padding:10px} .cnnArticleGalleryClose{background-color:#fff;display:block;text-align:right} .cnnArticleGalleryCloseButton{cursor:pointer} .cnnArticleGalleryNavPrevNext span{background-color:#444;color:#CCC;cursor:pointer;float:left;height:23px;text-align:center;width:26px;padding:4px 0 0} .cnnArticleGalleryNavPrevNextDisabled span{background-color:#444;color:#666;float:left;height:23px;text-align:center;width:25px;padding:4px 0 0} .cnnVerticalGalleryPhoto{padding-right:68px;width:270px;margin:0 auto} .cnnGalleryContainer{float:left;clear:left;margin:0 0 20px;padding:0 0 0 10px} Connecticut State Police Lt. Paul Vance addresses the press on Saturday, December 15. Twenty-seven people, including the shooter, are dead, including 20 children, after a deadly shooting rampage. Police officers stand at the entrance to the street leading to the Sandy Hook Elementary School on December 15. Corinne McLaughlin, a student at the University of Hartford, bows her head during a candlelight vigil at Hartford, Connecticut's Bushnell Park on Friday, December 14, honoring the students and teachers who died at Sandy Hook Elementary School in nearby Newtown earlier in the day. Distraught people leave the fire station after hearing news of their loved ones from officials on Friday. Emergency workers stand in front of the Sandy Hook Elementary School in Newtown. A child and her mother leave a staging area outside Sandy Hook Elementary School in Newtown, Connecticut, on December 14. Members of the media converge on December 14 in front of an apartment at 1313 Grand Street in Hoboken, New Jersey. The apartment is believed to be connected to the Connecticut elementary school shooting. Faisal Ali, right, of Colorado Springs, Colorado, joins other people outside the White House on December 14 to participate in a candlelight vigil to remember the victims of the Sandy Hook Elementary School shooting. Connecticut State Police spokesman Lt. J. Paul Vance, center, briefs the media on the elementary school shootings during a press conference at Treadwell Memorial Park on December 14 in Newtown. People weep and embrace near Sandy Hook Elementary School on Friday, December 14. A woman leans on a man as she weeps near Sandy Hook Elementary School on December 14. President Barack Obama wipes a tear as he speaks about the shooting at Sandy Hook Elementary School during a press briefing at the White House on December 14. A woman weeps near the site of a shooting at Sandy Hook Elementary School on December 14. A woman weeps near Sandy Hook Elementary School on December 14. People comfort each other near Sandy Hook Elementary School on December 14. A man takes in the scene near Sandy Hook Elementary School on December 14. A young girl is given a blanket after being evacuated from Sandy Hook Elementary School on December 14. State police personnel lead children from the school. Children wait outside Sandy Hook Elementary School in Newtown, Connecticut, after the shooting. A boy weeps at Reed Intermediate School after getting news of the shooting at Sandy Hook Elementary School on December 14. FBI SWAT team members walk along Dickinson Drive near Sandy Hook Elementary School on December 14. An aerial view of Sandy Hook Elementary School in Newtown, Connecticut on December 14. Connecticut State Troopers arrive on the scene outside Sandy Hook Elementary School on December 14. A Connecticut State Police officer runs with a shotgun at the Sandy Hook Elementary School in Newtown on December 14. Police patrol the streets around Sandy Hook Elementary School on December 14. People try to deal with the shock of the attack outside Sandy Hook Elementary School on December 14. Connecticut State Police secure the scene of the shooting on December 14. People embrace outside Sandy Hook Elementary School on December 14. A man escorts his son away from Sandy Hook Elementary School on December 14. People take in the news outside Sandy Hook Elementary School on December 14. People line up to enter Newtown Methodist Church near the the scene of the shooting on December 14. A woman speaks with a Connecticut state trooper outside Sandy Hook Elementary School on December 14. The streets around Sandy Hook Elementary are packed with first responders and other vehicles. A view of the scene at Sandy Hook Elementary School after the shooting. A young boy is comforted outside Sandy Hook Elementary School on December 14. People embrace each other on December 14. Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting Connecticut school shooting HIDE CAPTION << < 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 > >> Photos: Connecticut school shooting .cnnArticleGalleryNav{border:1px solid #000;cursor:pointer;float:left;height:25px;text-align:center;width:25px} .cnnArticleGalleryNavOn{background-color:#C03;border:1px solid #000;float:left;height:25px;text-align:center;width:20px} .cnnArticleGalleryNavDisabled{background-color:#222;border:1px solid #000;color:#666;float:left;height:25px;text-align:center;width:25px} .cnnArticleExpandableTarget{background-color:#000;display:none;position:absolute} .cnnArticlePhotoContainer{height:122px;width:214px} .cnnArticleBoxImage{cursor:pointer;height:122px;padding-top:0;width:214px} .cnnArticleGalleryCaptionControl{background-color:#000;color:#FFF} .cnnArticleGalleryCaptionControlText{cursor:pointer;float:right;font-size:10px;padding:3px 10px 3px 3px} .cnnArticleGalleryPhotoContainer cite{background:none repeat scroll 0 0 #000;bottom:48px;color:#FFF;height:auto;left:420px;opacity:.7;position:absolute;width:200px;padding:10px} .cnnArticleGalleryClose{background-color:#fff;display:block;text-align:right} .cnnArticleGalleryCloseButton{cursor:pointer} .cnnArticleGalleryNavPrevNext span{background-color:#444;color:#CCC;cursor:pointer;float:left;height:23px;text-align:center;width:26px;padding:4px 0 0} .cnnArticleGalleryNavPrevNextDisabled span{background-color:#444;color:#666;float:left;height:23px;text-align:center;width:25px;padding:4px 0 0} .cnnVerticalGalleryPhoto{padding-right:68px;width:270px;margin:0 auto} .cnnGalleryContainer{float:left;clear:left;margin:0 0 20px;padding:0 0 0 10px} Newtown High School student Trevor Lopez stands outside of a church where residents have come to pray and reflect on the violence at the Sandy Hook Elementary School on Saturday, December 15. Andrea Jaeger places flowers and a candle at a makeshift memorial outside a firehouse near Sandy Hook Elementary School on December 15. The U.S. flag flies at half-staff above the White House on December 15. Ken Kowalsky and his daughter Rebecca, 13, embrace while standing at the end of the road leading to Sandy Hook Elementary School on December 15. A woman puts a flower near crosses planted by Rio de Paz (Rio of Peace), in memory of the victims of the Sandy Hook Elementary school shooting on Copacabana beach in Rio de Janeiro on December 15. A woman sits during a service at the Asylum Hill Congregational Church in Hartford, Connecticut on Friday, December 14. Fans at the NBA game between the Utah Jazz and the Phoenix Suns participate in a moment of silence for the victims of the Newtown shooting on December 14 in Phoenix, Arizona. An overflow crowd listens to a church service held at the St. Rose of Lima Catholic Church in Newtown on December 14. People gather for a prayer vigil at St. Rose Church on December 14. People gather for a vigil outside the White House in Washington following the Connecticut elementary school shooting on December 14. Candles burn as people gather for a vigil outside the White House on Friday. Hartford, Connecticut, Mayor Padro Segarra speaks emotionally about the students and teachers who died earlier in the day at Sandy Hook Elementary School in nearby Newtown at a candlelight vigil at Bushnell Park in Hartford on December 14. Cynthia Alvarez is comforted by her mother, Lilia, as people gather for a prayer vigil at St. Rose of Lima Roman Catholic Church in Newtown. People gather for a prayer vigil at St. Rose Church in Newtown on December 14. People gather for a prayer vigil at St Rose Church in Newtown on December 14. People gather inside the St. Rose Church to remember the shooting victims on December 14. A woman bows her head during a vigil for the shooting victims on December 14. People gather in the St. Rose Church during a service on December 14. Women comfort each other during the vigil at St. Rose Church on December 14. A woman looks on during the vigial on December 14. People hug outside of the Newtown United Methodist Church on December 14, in Newtown, Connecticut, near the site of the shootings at the Sandy Hook Elementary School. A flag at the U.S. Capitol flies at half-staff after President Barack Obama ordered the action while speaking from the White House. Obama called for "meaningful action" in the wake of the school shooting. Julie Henson of San Francisco joins other people outside the White House to participate in a candlelight vigil to remember the victims at the Sandy Hook Elementary School shooting in Newtown, Connecticut on December 14, 2012. According to reports, the gunman killed 20 children and six adults. U.S. President Barack Obama wipes tears as he makes a statement in response to the elementary school shooting in Connecticut on December 14. Washington resident Rachel Perrone, left, and her 5-year-old son, Joe, center, join others outside the White House in a candlelight vigil on December 14. Faisal Ali, right, of Colorado Springs, Colorado, joins the vigil outside the White House on December 14. People gather outside the White House to participate in a candlelight vigil. Supporters of gun control hold a candlelight vigil for victims of the Sandy Hook Elementary School shooting outside the White House on Decmber 14. Newtown school shooting: World reacts Newtown school shooting: World reacts Newtown school shooting: World reacts Newtown school shooting: World reacts Newtown school shooting: World reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts Newtown school shooting: world reacts HIDE CAPTION << < 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 > >> Newtown school murders: World reacts Sandy Hook Emergency Dispatch Calls Principal's friend: 'The kids loved her' Suspected shooter's brother questioned Student: I saw bullets going past

Within minutes, Lanza killed 26 people with chilling efficiency, leaving only one wounded survivor, according to Vance. Among the adults killed were Dawn Hochsprung, the school's beloved principal, and school psychologist Mary Sherlach.

"Stuff like this does not happen in Newtown," said Renee Burn, a teacher at another school in the town, which is roughly 60 miles northeast of New York City.

Until Friday, only one homicide in the past 10 years had been reported in the upscale community of expansive homes surrounded by woods, where many residents commute to jobs in Manhattan and the nearby Connecticut cities of Stamford and Hartford.

Authorities found three guns next to Lanza's body in one of the classrooms, a law enforcement source told CNN. All three -- a semi-automatic .223-caliber Bushmaster rifle and two pistols made by Glock and Sig Sauer -- were owned by Lanza's mother, the source said.

Investigators know which one Lanza used to kill himself but are not yet revealing that information, the source said.

Lanza also had access to at least three more guns, a second law enforcement source said. Investigators recovered a .45-caliber Henry Repeating Rifle, a .22-caliber Marlin Rifle and a .30-caliber Enfield Rifle, though it's unclear where they were found, the source said.

One of the law enforcement sources said they have information that Lanza tried to buy a gun in the area this past Tuesday. The Bureau of Alcohol Tobacco and Firearms said it is contacting shooting ranges and gun stores in the area to try to establish whether Lanza sought to purchase guns or practice using them.

The number of young victims, between the ages of 5 and 10, sent shockwaves across the nation.

With the death toll at 26, the massacre in Newtown is the second-deadliest school shooting in U.S. history, behind the 2007 Virginia Tech mass shooting that left 32 dead.

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Flags were lowered to half-staff in a number of states, and vigils were held at houses of worship and at schools amid a national outpouring of grief.

Two law enforcement sources said Adam Lanza lived with his mother. Contrary to early reports, they said, Nancy Lanza was not a teacher at Sandy Hook Elementary.

Investigators believe Lanza killed his mother and then took her guns and made his way to the elementary school wearing black fatigues and a military vest, according to a law enforcement official.

At about 9:30 a.m., as announcements were read over the loudspeaker to the nearly 700 students, the first shots rang out.

Students described being ushered into bathrooms and closets by teachers after hearing the first shots.

It sounded like "pops, gunshots," Janet Vollmer, a kindergarten teacher, said.

Vollmer locked her classroom doors, covered the windows and moved her 19 pupils toward the back of the room.

"We're going over in a safe area," she told the 5-year-olds. Then, she opened a book and started to read.

Outside Vollmer's classroom, a gunman was moving through the hallway of the one-story building.

In the first few minutes, the gunman is believed to have shot the principal, Hochsprung, and the school's psychologist, Sherlach.

One parent who was at the school in a meeting with Hochsprung, Sherlach and the vice principal said she heard a "pop, pop, pop." All three left the room and went into the hall to see what was happening. The parent ducked under the table and called 911.

"I cowered," she told CNN. The gunman "must have shot a hundred rounds."

At the police station, dispatchers began to take calls from inside the school.

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"Sandy Hook school. Caller is indicating she thinks someone is shooting in the building," the dispatcher told fire and medical personnel, according to 911 tapes.

Then, another caller reported gunshots. And then another.

"Units responding to Sandy Hook School at this time; the shooting appears to have stopped. The school is in lockdown," the dispatcher said.

The dispatcher warned police and medical personnel that callers were reporting "multiple weapons, including one rifle and a shotgun."

Then, a police officer or firefighter called for "backup, ambulances, and they said call for everything."

The dispatcher, according to the 911 tapes, asked how many ambulances were needed.

"They don't know. They're not giving us a number," the officer or firefighter said.

Inside a classroom, Vollmer was still reading to the children when police officers banged on the locked door.

The kindergartners were told to line up and cover their eyes as they were led by police past bodies, presumably of their fellow schoolmates, Vollmer said.

As reports of the shooting made their way around town, frantic parents descended on a nearby firehouse where the children had been taken.

"Why? Why?" one woman wailed as she walked up a wooded roadway leading from the school.

Inside the firehouse, Vollmer's kindergartners were beginning to understand something terrible had happened.

"They saw other people upset," Vollmer said. "We just held them close until their parents came."

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By nightfall, the firehouse became a gathering point for parents and family members whose loved ones would never walk out of the school.

Authorities, meanwhile, in Hoboken, New Jersey, were questioning Ryan Lanza, the suspected gunman's older brother, law enforcement sources said, though they did not label him a suspect. Lanza's father, Peter, who lives in Connecticut, was similarly questioned, one of the law enforcement officials said.

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