Authorities could not provide a reliable estimate of how long gunman Salvador Ramos was inside Robb Elementary during Tuesday's attack.

A gunman massacred 19 children and two teachers in a Texas elementary school before law enforcement agents stormed the classroom and stopped his rampage. This prompted questions and criticisms about the length of time before law enforcement agents intervened.

Investigators were also unable to state whether an armed school district security officer had fired upon the attacker, 18-year-old Salvador Ramos when he first arrived at Robb Elementary in Uvalde on Tuesday.

The motive for the incident, which was the bloodiest school shooting in the United States since Newtown, Connecticut, a decade ago, remained under investigation, with investigators stating that Ramos had no known criminal or mental health background.

According to witnesses, during the standoff, which ended when a Border Patrol team rushed in and fatally shot Ramos, agitated bystanders urged police authorities to storm the school.

Juan Carranza, 24, who observed the event from outside his home across the street from the school, reported that women yelled, "Go inside! Go in!" to the officers shortly after the assault began.

On Wednesday, Steve McCraw, director of the Texas Department of Public Safety, stated that between forty minutes and an hour had passed between when Ramos began to fire on the school security officer and when the tactical team shot him.

However, a department spokesperson later stated that authorities could not provide a reliable estimate of how long the shooter had been in the school.

"The bottom line is that law enforcement was present," stated Mr. McCraw. "They quickly engaged. "(Ramos) was contained in the classroom."

In the meantime, a law enforcement official reported that the Border Patrol agents had difficulty penetrating the classroom door and had to use a key to unlock the room.

Javier Cazares, whose daughter Jacklyn Cazares was slain in the incident, stated that he rushed to the school as soon as he heard about the shooting, arriving as police were still assembling outside.

He was upset that police were not going in, he proposed that he and several other witnesses storm the school.

"Let's just rush in because the police aren't carrying out their duties," he remarked. More could have been accomplished.

"They lacked preparation," he continued.

Mr. Carranza stated that he witnessed Ramos smash his truck into a ditch outside the school, take his AR-15-style semi-automatic rifle, and shoot two uninjured individuals outside a funeral home.

Lieutenant Christopher Olivarez of the Department of Public Safety told CNN that the security guard outside the school was armed. Initial reports indicated that he and Ramos exchanged shots. However, we are attempting to confirm this information, stated Lieutenant Olivarez.

After entering the school, Ramos secluded himself in a classroom and commenced his murderous rampage.

Mr. Carranza stated that authorities need to have entered the school earlier.

"They were more numerous. "There was only one of him," he explained.

Meanwhile, hundreds gathered at the town fairgrounds on Wednesday night for a healing vigil where speakers gave prayers.