it's unlikely the murders were done by a single shooter >> to me there's -- structurally difficult for the same shooter to have two arms and no practical reason for that to happen >> reporter: and after lunch the final defense witness. alex murdaugh's younger brother, john marvin >> it's the hardest thing i've ever been through in my life >> reporter: giving emotional testimony about returning to the crime scene the day after the murders to clean up paul's remains, including pieces of his skull. >> and i can promise you, no mother or father or aunt or uncle should ever have to see and do what i did that day >> reporter: john marvin also recounting how during a visit to assist s.l.e.d. investigators he was offered false information about case evidence >> but described the white t-shirt covered in blood even went so far as to describe that alex took the bottom of it and wiped his face with it. >> reporter: the