As stated previously, I do lean to RA being the perpetrator more likely than not. I do not however see a great deal of value in the 4 witness statements. First, the 3 juveniles are inconsistent enough in multiple facets of how they describe "the male they encountered" to cast overall doubt. Secondly, the woman walking alone has obviously already seen L's video by the time she provides her account to LE as she states the person she saw on bridge matched the appearance of he in L's video. None of the 4 specifically identify Richard Allen, or... the guy who works at CVS, or ____ Allen's husband, or _____ Allen's father, etc. The 4 people's accounts may corroborate the person we call BG, but we already have much stronger physical evidence (via L's photo/video) of what BG was wearing and looked like, and that yes BG would've been both en route to the bridge (the juveniles' account) and that BG was likely on the bridge within minutes of the encounter w/girls (Woman's account). The only unique value to the these witness statements is that they may confirm the specific route BG took in arriving at the bridge thus possibly where he parked, plus that he entered the bridge from the commonly-used access point and walked the entire length as opposed to entering from the side/access point they all later exited. In the end though, the dots being connected that RA is BG remain lacking, other than RA volunteering info that places him within 1/4 mile of the encounter scene (though he denied ever being to the actual murder scene) and in a reasonably similar timeframe as the crime occurred. Is the fact that no one else was seen nearby at the right time, or the supposition that "who else could it be" enough to convict of double-murder via this negative confirmation?
MOO I personally think the unspent casing is by far the strongest piece of evidence tying RA to being the perpetrator from a common-sense standpoint. Unfortunately, as many on this site agree, there are likely many experts who can be found to testify that leans toward junk science and is not reliable from a purely legal standpoint.
The Timeline I would describe as plausible, but I wouldn't MOO say beyond tight. All of us, including the video producer himself Gray Hughes who've watched his video, admit quite a few challenges in reconciling the various surveillance camera/phone evidence to the paces that certain individuals had to be moving at. This was discussed in great detail a few months back, but at times the key players have to be traveling at a snail's pace from point A to B, while at other times a near-sprint is required. It doesn't seem as tidy as we would like.
It's very possible you're correct that RA might be lying in parts of his statements to LE/CO. He may actually be lying in all of his statements?? However it's a challenge to reconcile why he'd come forward at all, especially early on when he didn't have to if he was going to provide a mixed bag of truths and lies. It's easy for us to believe he told the truth when it fits with our believed narrative and was lying when it doesn't fit.
Again all JMO