They discovered the bullet came from the officer's gun (the stolen gun) but I believe the CCTV wasn't enough to determine who actually fired the shot, and I haven't read anything about eyewitnesses, unfortunately. They eventually carried out a crime scene reconstruction, which I now edited and included in my article, but I couldn't find the conclusion online. If I find any piece of information that clarifies this, I will include it in the article and let you know!