What about if what they did find (MM related) is some sort of text ?
Just guessing here but something like a CB journal/diary where he did wrote about killing MM ?
What if the text is some sort of interception of chat/skype over the internet where CB did talk to someone else about killing MM, like a "continuation" or follow up of that conversation where he stated he wanted to abuse something small ? Maybe BKA have more of those chat interceptions either on skype or even pedo forum/chats on Darkweb or whatever and there aree text from CB saying he did kill MM ?
And also there are many pedophile forums over the DarkWeb and even on the clearnet that are about text only as those are "legal" on most of the countries. Those "forums" or sistes are dedicated to share/collecting pedophile "stories" and make-up or false/untrue/imagination stories or child abuse. Same way for example on Japan there are a huge amount of "lolicon" and many mangas/animes of "Hentai" content with underage children that sometimes are even baby/toddler and are considered "legal" in most countries as those are "not real", meaning that CB could even have posted somewhere a "story" about killing MM and maybe it's something like that ? Not very likely I know, but it's a possibility.
If BKA does indeed have "something" solid I would be more inclined to think that it's either something like an old friend/s statement as i told here before or it's some kind of comunication interception.
Finaly it might be audio instead of text as well, maybe CB did phone/skype someone and told that person about killing MM ? Problem is that if that were to be the case the other person would be involved as well and HCW is stating CB did act alone. Of course HCW might be "lying" in an attempt to get the other person as well but there are another option, maybe CB did "confess" to a priest or someone like that ? What about if CB told a "priest" in confession that he did kill MM ?
Just leaving some ideas, don't get me wrong, i'm not trying to change the opinion of you guys regarding what HCW "might" have. The truth is that he did hid that info so well that all that we can do is guessing.
I trully think that we will be running in circles with this unless HCW provide us more details or at least some more "hints" about what kind of "evidence" he does have regarding CB/MM.
The only thing that i trully hope is that he end up telling us something when the investigation is over even if it's not enough for charging so that we can make our own judjment about CB/MM. Meaning that even if what HCW have is not enough to charge CB with the crime if that "something" is something "solid" like a text interception where CB does confess MM killing for me it's enough to make up my mind about his guilt, because for me even if the law itself can't put him on jail i will be more convinced that he is guilty, like the Ulvi guy and the Manuel guy on the PK case, thart even if they were "aquitted" by justice fail and bad conducted investigation for me there is no doubt that they are guilty even if the system did fail on that case.
Now if HCW doesn't have anything "solid" and if all of what they have is something like a "speculation" or oppinion of an old friend that "thinks" that CB "MIGHT" have killed MM that will not be very satisfying and people that are investigating and following this specific case like all of you guys will need to start looking for other possible suspects once again ... Let's hope in some ways that this time BKA does have the correct guy so that this case can finaly be put to rest and MM family might have their closure knowing what did happen to MM.