I think BG is male, and fair skinned (probably Caucasian). This is obvious from Libby's video.
BG looks like a highschool senior or college kid, but his voice sounds mature. I'm guessing he is in his late 20s. JMO.
I think BG is a member of the Delphi community (not a transient), but not necessarily a full time resident. This has been asserted by LE, and makes sense in the context of the killer having to be familiar with the trails and bridge.
I think BG is youthful in appearance and clean-cut, leading me to infer that he has led a somewhat privledged lifestyle. I think he would look more aged if he were an addict or alcoholic or homeless. This is just my opinion based on how I reacted when I first saw the new composite.
I think BG either owns a vehicle or has access to one. This is based on the reference in the presser to the parked car, and LE seeking tips about the identity of its driver.
I think BG is in a relationship of some type, and is likely a husband/father and/or son. This is in reference to Carter's presser referring to Abby & Libby as 'little girls' as well as stating something along the lines that the people close to BG will be shocked and horrified when they learn of his brutal crimes.
I think it is possible that BG is religious. This is based on the timing of the presser (Good Friday/Easter Monday), as well as the references in the presser to The Shack, and appealing to his conscience. It could be a stereotype, but I often assume that people from a small town are religous and that many of their community activities revolve around the church.
I think BG has been blending in with the community since the murders. This is based on Carter's reference to 'hiding in plain sight'.
I think BG either owns or has access to a gun or recently bought/sold one illegally. This is based on my gut instict that a gun was used to control the girls, but not necessarily to kill them.
I think BG is comfortable in nature and may be outdoorsy (camper; hiker; hunter; fisherman). JMO based on the crime being committed in the woods.
I think BG may work in a position of power or authority (LE, teacher, coach, youth pastor, government figure etc...). This is based on the information at the presser stating that this is about 'power' to BG.
I think BG may have been feeling very powerless in his life back in Feb. 2017, and experienced a traumatic event (divorce, death in family, loss of job etc...) that led him to be angry, anxious or experience a bout of mental illness. JMO based on the notion that a 'sane' human would not brually kill two innocent children.
I think BG had the opportunity to commit this crime on a Monday afternoon without anyone being overly suspicious, which leads me to believe that he is/was unemployed, a seasonal worker, a shift worker, on a paid or unpaid day off, or works in close proximity to the trails.