Timeline and What We Know – NBC Los Angeles

A gunman stormed into an elementary school Tuesday in Uvalde, Texas, killing 19 children and two teachers in the United States’ deadliest school shooting in nearly a decade.

Law enforcement officers killed the gunman, identified as a local 18-year-old who had shot and wounded his grandmother and spelled out his violent plans in online messages shortly before the massacre at Robb Elementary. Investigators say they don’t yet know a motive for the shootings.

Here’s a summary of what we know so far about the gunman and shooting, according to state and federal law enforcement officials:

• Salvador Ramos turned 18 on May 16. The next day he bought the first of two AR-15-style rifles from a federally licensed gun dealer in the Uvalde area.

• On May 18, he bought 375 rounds of ammunition, and on May 20, he bought the second AR-15-type rifle. One was a Smith & Wesson M&P 15. The other was a Daniel Defense Model DDM V7, for which he also bought a laser-aided sight. NBC News estimates the total cost was at least $3,500.

• Sometime around 11 a.m. CT time on Tuesday, he wrote in a private Facebook message, “I am going to shoot my grandmother.  He then shot the 66-year-old in the face and wrote “I shot my grandmother.” A bit later, he wrote, “I’m going to shoot an elementary school.” The grandmother managed to run to a neighbor’s house and report the shooting, and police responded to her house. Facebook spokesman Andy Stone says the messages “were private one-to-one text messages that were discovered after the terrible tragedy.”

A Facebook spokesman says messages posted by the gunman were private. Andy Stone says the messages “were private one-to-one text messages that were discovered after the terrible tragedy.” He says Facebook is cooperating with investigators.

• The shooter took off, driving the grandmother’s truck, and crashing it in a drainage ditch near the school. He ran toward the school, carrying the Daniel Defense rifle and a backpack with extra ammunition magazines. The Smith & Wesson was found on the ground outside the car.

• A school resource officer confronted him, but the gunman kept going, got into the building and down the hallway, entering a double classroom and locking the door. He then opened fire around 11:30 a.m.

• A law enforcement team — including local police and a tactical team from the U.S. Border Patrol — arrived but was unable to enter the classroom.

• They finally got the door open when the principal produced a master key. Agents exchanged gunfire with the shooter, killing him.

• Meanwhile, other officers and who responded traversed the school grounds and shattered windows so teachers and students could escape.

What Don’t We Know?

Authorities haven’t disclosed a full list of the victims. Nor have many important details about the attack been made public.

Among them: what transpired between the gunman and the school officer who first encountered him; who saw the online posts attributed to him; what, if any, history he had with Robb Elementary; and why he went on the rampage.

“We don’t see a motive or catalyst right now,” Texas Public Safety Director Steve McCraw  said Wednesday afternoon.

The two co-teachers killed along with 19 children in the mass shooting at Robb Elementary School in Uvalde, Texas, are being hailed as heroes for attempting to shield their students from the gunman in their final moments. NBCLX storyteller Clark Fouraker shares what we know about longtime educators Eva Mireles and Irma Garcia.