I've seen the video and it don't look good for the 2 men that confronted that young man.
The police were already called,
it was stated the son seen a video tape of the break in at a neighbors home a week earlier and said Arbery looks like one of the person that broke in, so when the father seen a black boy running on the road he called his son and that's when they decided to do an armed confrontation and drove ahead of Arbery and stopped the truck, one guy got out of the pickup with a shotgun and confronted Arbery after a shot was fired, if you look close at the video Arbery was already bleeding before the man confronted him in front of the truck meaning he was already shot before Arbery grabbed the shotgun in what appears Arbery trying to defend himself.
From what I seen Arbery was jugging and not running, it appears the father son confronted and killed the wrong man, I think GBI came to the same conclusion. What is going to go against these men is that they already called the police, instead of waiting they decided to get in the truck and chase him down armed and as the result we have a dead man and more than likely an innocent dead man. The local didn't botch the investigation they tried to bury it, the DA was friends with the father involved in the shooting, both the Chief and DA stated an outside agency doesn't need to be involved meaning they didn't want the GBI involved.
From what I read this morning the GBI may call in the FBI to investigate everyone from mayor to dog catcher, this isn't the first incident from that town according to the GBI. The police department investigated this for two weeks and stated there were no evidence for the arrest and listed it self defense, the local police also dismissed the video. GBI goes in to investigate and within 36 hours found more than enough evidence to arrest the two man on murder charges and state more arrest may be coming, they are also investigating the local investigators.