From the DSO:
"Video is of Dallas County Sheriff's Deputy K. Caldwell as she rushes to get ahead of the oncoming armored van driven by the suspect that shot at Dallas Police Headquarters and at Dallas Police Officers on June 13, 2015. Deputy Caldwell was on Westbound I-20 and took the Hwy. 310 Exit. She turned right and set up her vehicle as Dallas Police and the armored van they were chasing could be heard approaching her location. With just a few seconds to spare she throws and extends the "Stop Sticks" out into the road. A few seconds later the van runs over the "Stop Sticks" effectively puncturing some of the tires on the armored van. The chase lasted a few minutes longer as the van got on Southbound I-45 and took the Dowdy Ferry Rd. Exit coming to a stop at a Jack In The Box Restaurant. See video 2 for what happened as the Deputy pulled in to the parking lot."Here's video two: