Authorities have released more information regarding the police officer shooting of Walter Scott. Last weekend, cell phone footage surfaced showing South Carolina officer Michael Slager pursuing and then shooting a fleeing Scott several times in the back.

The video evidence itself was damning, but it left a lot of people wondering what could possibly have happened to provoke such a seemingly vicious and senseless attack. Yesterday, authorities released “dash cam” footage that reveals what happened in the minutes before the cell cam footage picks up:

The video depicts the moments leading up to the fatal shooting: the officer is seen calmly walking up to the car, occupied by Scott and a second passenger, and asking Scott for his license and registration; Scott says that he is not the owner of the car, but planned to buy it soon. The exchange is cordial.

When Slager went to run Scott’s record in his car, Scott ran, allegedly because he was worried that he’d be arrested for late child support payments. Seconds later, Slager gave chase, leading to the second video taken by a bystander.

Watch:

Here’s the full video of Slager’s attack on Scott:

On Tuesday, Slager was charged with murder.