Friday marks one year since a gunman opened fire in Downtown Dallas, killing five police officers and injuring nine more.

Tyler Police Department Assistant Chief Rusty Jacks said the attack highlights new dangers faced by today's officers.

"Officers have always known it is a dangerous job because we're going out there and confronting criminals," said Jacks, a 23-year veteran of Tyler PD who oversees the patrol division. "They almost expect that if there's going to be a problem it's going to be on a contact with someone. Before a couple years ago, it was almost unheard of for officers to be ambushed and assassinated. The Dallas shooting brought that to light."

Along with new challenges, the Dallas shooting also brought changes in the way TPD officers do their jobs.

"Not just our department, I think all departments around the country have probably increased training for officers in tactics, equipping their officers with medical equipment to be able to respond and help a fellow officer or citizen who's been injured."

While new protective equipment and training have been implemented, Jacks said something else has also helped officers.

"Part of what has helped is that public support has turned, and here especially in Tyler, Texas we have a lot of public support," he said.

In remembrance of the Dallas ambush, Texas Gov. Greg Abbott has issued a statewide call to stand with law enforcement on Friday.

He has asked all the state's law enforcement officers to activate their red and blue emergency lights for one minute at 10 a.m.