KAK is a known deviant with a sexual interest in chiildren--he admits that. He also admits to having been in contact with Libby, among others, and seemed (in the transcript, MHO) not to object when LE said he was the last outside person known to be in contact with Libby other than the murderer.
After the murders another girl who had been in contact with KAK reported a Peeping Tom to the local police. After the murders, KAK apparently went to Las Vegas for several days (the timelines still aren't clear to me.) KAK put a bunch of "work history" on facebook that included his being hired as a casino card dealer the same day as the murders--but we know he posted that over a year *after* he claims it happened. No casino reported knowing KAK to the "Murder Sheet" podcasters.
KAK admits that he wiped information from his electronic devices, and presumably hid his main phone when his house was searched two weeks after the murders. Many of us assume he did so to hide criminal evidence.
Over a year after the murders, TK, KAK's father, posted a message on FB with a picture of KAK saying "my boy is coming home--he hasn't been here in over two years." The 'over 2 years' is greatly incorrect and TK must have lied deliberately since he apparently was with KAK immediately after the murders. Many of us assume TK did this to provide a pathetically weak and laughably fictional alibi for his son.
Those are the major points as I recall them, Gypsy Lass. I would add that the pictures of KAK from the Las Vegas trip *to me* and this is just my opinion, look to me that he easily could physically be Bridge Guy from the video.
All this is just my own poor opinion. I also think law enforcement has more evidence than we know, pointing to KAK, but he's in jail and not getting out any time soon, so there's no urgency in an arrest. (shrug) JMHO.