Five officers' lives were taken the night of July 7, 2016, after a gunman ambushed officers in Downtown Dallas following a protest.
Along with the officers killed, several were injured, along with some civilians from that night.
The Dallas College El Centro campus downtown was where the suspect ended up and led a shootout with police.
Dallas Police used a remote-controlled robot with an explosive device to kill the suspect.
No students were injured that night, but two campus police officers were wounded. Many credit the former police chief of the college, Joseph Hannigan, for his heroic efforts that night which saved lives.
"He stepped up to the plate, he made sure that the officers who were there knew exactly what they needed to do, he communicated with incoming officers," said Lauretta Hill, current chief of public safety and security for the Dallas College Police Department.
She had not started ad CDPD yet when the shooting happened, but reflected on her former colleague's quick thinking.
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"He did was what he was trained to do, but it also showed his leadership and the fact that he was ready to jump into action," said Hill. "He helped contain the situation, obviously as Dallas Police and more officers arrived to engage the suspect, so his actions were heroic that day."
Hannigan died last Dec. from pancreatic cancer, he was 60 years old.
Since 2016, the college has invested in equipment and training to prepare officers for a major threat, with the continued goal to save lives in the event something unfortunate of that magnitude ever happens again, according to Hill.