Originally Posted by Lerxst
Dassey said he witnessed Avery shoot Teresa with his .22 in the garage. After this admission by Brendan, Investigators find a .22 spent bullet from Avery's 22 rifle with the victims DNA on. They also got a luminol reaction in the exact spot Brendan said he cleaned up the blood. Brendan also knew there were human bones hidden in the quarry pit.
Hence he is guilty of being party to a murder and helping to cover it up.