My theory is that DM and MS exited the truck when it was parked in the field, behind the haybales, probably saying they needed a moment to relieve themselves after the long drive. DM left his window down on the driver's side. When they came back DM shot an unsuspecting TB suddenly through the open window, or he opened the driver's side door and shot while still outside the truck, then MS took his shot from outside, on the driver's side as well. He may have waited to make sure TB did not get out of the passenger side door, then had his turn. This way they were both outside the truck and safe from bullets bouncing off metal inside the truck, and also safe from a possible struggle with poor TB, or having so much ringing in the ears from being in an enclosed small space while shooting. They may also have used some kind of silencer that we do not know about. To murder him this way, and not put themselves at risk, made it necessary for them to be willing to cause damage to one window, and have blood inside the truck, which they thought they could clean up later. When a shooter reached inside the truck to shoot, the bullet casing could eject into the back of the truck easily, where one was found. This is the way cowardly criminal psychopaths operate.
IMO
