A new surveillance video in connection to the Texas shooting at Robb Elementary School revealed that armed police officers were already at the Uvalde school but waited for 58 minutes before entering the classroom where the gunman and the children at.

San Antonio Express-News reported that surveillance footage also showed that police never attempted to open the doors to the adjoining classrooms full of children when the gunman, Salvador Ramos, was inside.

The police reportedly did not attempt to enter the doors until keys were obtained, which took place more than an hour after the gunman entered the Uvalde school, according to Spectrum News 1.

According to reports, 77 minutes elapsed between when Ramos entered the school through an unlocked door and when the cops fatally shot him.

A source told ABC News that investigators believe that the gunman may not have locked the doors to the classrooms from the inside.

The insider went on to say that the surveillance video also showed that Ramos was able to open the door to classroom 111 from the outside. The said classroom is connected to the adjacent classroom 112.

Reports noted that an investigation if one or both of the classroom doors were unlocked while police were outside remained under investigation.

The source said that footage showed that the gunman fired rounds inside classrooms 111 and 112, briefly exited into the hallway, and then re-entered through the door.

Ramos then shot at the police officers through the closed door, grazing two cops with shrapnel, and the officers retreated to wait for backup rather than force their way into the classrooms.

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Image Shows Police With More Firepower During Uvalde Shooting

The surveillance footage also revealed that the police, who responded to the May 24 tragedy, had more firepower than the gunman. 

The footage showed that law enforcement authorities have at least one ballistic shield, and officers carry their rifles while inside the Robb Elementary School.

Investigators think that the recent footage will prove to be a significant development, as the video indicated that the law enforcement had more than enough firepower and protection to enter the classroom where the children and the gunman were.

It can be recalled that District Police Chief Pete Arredondo reportedly called the landline at the Uvalde Police Department for help, claiming that their officers needed to be outside the classroom because they did not have enough firepower to confront the gunman.

The new surveillance footage came as the response of the authorities was placed under scrutiny after the Texas DPS revealed that officers waited more than 70 minutes to confront the shooter, even though students called 911 for help.

Texas Shooting: The Tragedy at Robb Elementary School

The Texas shooting at Robb Elementary School occurred after Salvador Ramos, 18, entered the site carrying an AR-15 rifle. At least 19 children and two teachers died after the 18-year-old gunman opened fire.

Tactical officers killed Ramos during a shootout in a classroom after he went on a killing spree at the Texas school.

Authorities discovered that Ramos posted a warning on Facebook before committing the act. Despite killing 21 people, Ramos' mother claimed that the shooter was not a "violent person." However, the mother acknowledged that her son did not have many friends.

READ MORE: California Teen Arrested After Threatening a School Shooting on Social Media

This article is owned by Latin Post.

Written by: Joshua Summers

WATCH: Uvalde Surveillance Image Shows Officers Arrived With Rifles Within Minutes - From  KVUE