FORT WORTH (CBSNewsTexas.com) -- The criminal trial for 19-year-old Timothy Simpkins continues Wednesday morning. 

He is charged with attempted murder connected to a 2021 school shooting at Timberview High School in Mansfield ISD.

On the first day of the trial, several teachers and a former student recalled running for their lives from a classroom after a teenager started shooting in October 2021.

On day two of the trial, video was shown publicly for the first time of teachers and students rushing out of a classroom and running down hallways as a student emerges behind them firing a gun.

A security camera inside the high school captured the chaotic scene. It was played for a jury during the trial.

Day three of the trial continues Wednesday. 

Read a full recap of the first day of the trial here and a recap of day two here.