Okay, don’t have much knowledge of these things and I don’t watch forensics dramas on tv, but... if blood is coming out of the mouth, doesn’t that mean the lungs were perforated? Does one commit suicide by shooting oneself in the chest?
There was no bullet chest wound to my knowledge. The area the chest where the shirt appears discolored could have been caused by several things. I would guess when the image was obtained, the suspect was already handcuffed. Standard procedure even if the suspect is dead. The dark marks or blood marks on the material could have been made during the process of moving the suspect to cuff him, or by the suspects own hand touching his shirt prior to being cuffed etc...