Wow awesome sleuthing everyone! Kudos to black_squirrel for finding the connection, clearly you are a valuable asset to the websleuths community. :clap:
I don't know Chelsea but have followed her disappearance closely, she went missing about 5 miles from where I grew up & I've even been to a few parties at MW house in the past. I initially joined Websleuths for the Julia Niswender case, I knew her and have been a close family friend for years. There has been a lot of speculation that these two cases could be related, I however do not believe this to be the case. I believe Julia's murder was well planned & very personal while Chelsea's disappearance may have been well planned, the choice of a victim was whomever happened to be in the wrong place at the wrong time.
Based on what we know about Chelsea, under normal circumstances it doesn't seem likely she would accept a ride from someone she didn't know but at 3 am, not wanting to call & wake up her mom & unable to reach another ride home she very well may have.
I think you're all onto something with Hero, I hadn't even thought of the possibility of him being involved with her disappearance but I could never wrap my head around his explanation for lying to LE. Reports say he saw two men harassing Chelsea & helped her into a car which drove away & she was not to be seen again. This doesn't make him sound like a hero at all, she's missing & if the story were true then he actually failed in protecting the bleeding woman who was being harassed. I think the suggestions that he initially believed she would be found & wanted to provide an explanation of why he may be linked to her in someway are spot on. When she wasn't, he wanted it all to go away so he claimed it was completely made up. I also believe the resemblance between the sketch and hero's Facebook friend are uncanny.
Sketchy guy twin posts of drug use on multiple occasions so I would assume the abandoned building within walking distance of your home would be a great place to get away & use drugs for those still living with their parents. Being comfortable with the area & knowing it was pretty secluded would make it a prime spot to take the woman you've just abducted. I may be starting to go into left field with this one but the captor/s may have spent many nights there using drugs & hatching a plan for an abduction.
Another scenario could be one of the boys feeling LE could be getting close panicked & placed the evidence he may have still had in his possession there to implicate his friend/s or to steer the investigation in a different direction. Although if it were the latter, I doubt they would plant the evidence so close to home. I am leaning toward it being left by accident & Chelsea's abductors never returning to the site in order to avoid being linked to the building in any way. Judging by the posts on Facebook, the group may not be the brightest crayons in the box.
Ultimately, I think LE is very close to having the answers in both Julia and Chelsea's cases. These girl's and their families are on my mind & in my prayers daily.