Hutchins High School earlier this week unfolded in less than two minutes and began when another student let the armed suspect inside through a locked side door, Dallas ISD Police Chief Albert Martinez confirmed Thursday.

Five students were injured in a shooting Tuesday afternoon at Wilmer-Hutchins High School in southeast Dallas when a 17-year-old allegedly snuck into the school and fired “indiscriminately,” according to a state affidavit for the suspect’s arrest warrant.

Police were investigating a reported shooting Tuesday afternoon at Wilmer-Hutchins High School in Dallas, a department spokeswoman confirmed to The Dallas Morning News. Officers were dispatched about 1 p.m. to the school in the 5500 block of Langdon Road. A police call log showed 19 units at the scene.