Area hospitals reported Friday that they had treated 14 people for injuries related to the shooting.
A 20-year-old man kills his mother in Newtown, Connecticut, in December 2012 before blasting his way into Sandy Hook Elementary School and shooting dead 20 six- and seven-year old children and six adults.
According to a statement obtained by Homero De La Fuente of CNN, officials at the school were told Watt will pay for the funerals of those killed in the attack.
Freshman Abel San Miguel saw his friend Chris Stone killed at the door. Students were led to take cover behind a auto shop across the street from the school.
Students said Pagourtzis was known for wearing a long black trench coat, unusual attire in a part of Texas that is often hot and humid. Braun and other officials declined to answer questions about the investigation.
Dead in Texas School Shooting Identified
Houston Texans defensive end JJ Watt has always been known for his connection to the Houston area, and has offered to pay for the funerals of the 10 people killed in the shooting. Braun says the officer remains in critical condition.
A teacher at the school, Cynthia Tisdale, was also identified as a victim by her brother-in-law, John Tisdale, reports said.
"He chose to chicken out of that and came out with his hands up", County Judge Mark Henry told the newspaper on Saturday. But the canisters had no detonation device, and the pressure cooker had no explosive material, Henry said.
Classmates at the school of some 1,460 students described Pagourtzis as a quiet loner who played on the football team.
A Pakistani exchange student, Sabika Sheikh, was killed in the shooting.
He called his daughter's friends, but they weren't responding either.More news: A New NAFTA Deal Doesn't Seem Close, Despite Deadline
Santa Fe High School freshman Peter Matuza said he was in art class Friday morning when he heard two explosions and ducked under a table.
Fighting back tears, her father told The Associated Press on Saturday in Karachi that Sabika was due home in about three weeks for the holiday marking the end of Ramadan.
"Give us our time right now, thank you", she said.
Abbott said there are "one or two" other people of interest being interviewed about the shooting.
The gunman yelled "Surprise" before he started shooting, according to Texas Rep. Michael McCaul, the chairman of the House Homeland Security Committee.
McCaul said late Friday that Pagourtzis wore a trench coat despite the sweltering temperatures earlier that day "to hide the shotgun and.38-caliber underneath" during the attack at Santa Fe High School near Houston.More news: Hawaii volcano Kilauea erupts with 9000-meter ash plume
What we know about school shooting suspectThe suspected shooter, who is in custody on murder charges, also had explosive devices, including a Molotov cocktail, that were found in the school and nearby, said Gov. Greg Abbott, who called the assault "one of the most heinous attacks that we've ever seen in the history of Texas schools".
The University of Texas Medical Branch tweeted the update Saturday.
Since 2003, more than 1,100 Pakistani high school students have studied in the U.S. under the YES programme, according to the organisation's website.
It was the nation's deadliest such attack since the Florida massacre that killed 17 and energized the teen-led gun-control movement. He was being held Saturday without bond. Pagourtzis told an investigator he acted alone and spared people he liked because he wanted his story told, the probable cause affidavit says.More news: Call of Duty: Black Ops 4 Playable Female Characters Revealed