Am I missing something? Do we know why there was no way for law enforcement to contact Jack?
From the interview, it seems George knew his last name. Jack was one of Becca's friends and would likely have more information about her, whether her identity or pointing LE towards friends that would know more about her.
It seems like getting info about Becca in front of her friends is the missing puzzle piece here, it's just unknown how to do that. It's really sad to hear she had a very close childhood friend that was likely missing her and looking for her. Perhaps they just didn't know to look for a decedent, or gave up by the time the Internet was widespread.
It's sad that we have a name she went by, a general location she lived in, and we know she had close friends that would likely be missing her, there's just been no way to put the puzzle pieces together yet.