By "X" , I assume you are referring to KAK.
In the past 5 plus years, there have been several people surface in the news that seemed to be potential POI . None of them have ever had a proven link to either of the girls.
Then, in December of 2021- the ISP actually make a plea on YouTube for information about an account for someone calling themselves Anthony Shots. The officer that was in the video made a statement saying it was in relation to The Delphi Murders.
That is the initial interest...
Now...let's add that since then , the transcripts of KAK being interviewed by LE while he sits in prison include information that KAK did in fact have contact with LG , was arrested for CSAM (which prove an interest in very young girls ranging in age from 3 up to their mid teens) , the fact that AS had sent messages to LG after her death, exchanged texts with a frined of LG's saying he was supposed to meet her the day that she was murdered, looked up "How long does DNA last?," repeatedly looked uany information about the murders while on vacation with his father, and seemed to have an interest in looking at photos of dead children.
Also- the fact that LE has shown interest in KAK's own father - who has a super violent history - and has since ceased contact with KAK for reasons unknown ( we can insert our own theories here) seems to be a pretty convincing argument that there is a pretty good cause for the belief that KAK has involvement in what happened to the girls in Delphi on February 13th, 2017.
There is actual proof (for the first time in this case) that KAK has a connection to LG and was wiping his phone of any information that could incriminate him in the case.
Now- IMO- KAK sounds like the voice on the recording...AND I don't believe that he is in any way the dumb innocent oddity that he has painted himself to be. I think that with the help of someone else, he became more and more cunning, calculating and invested in his involvement in this case. That is MOO .