Mafia 80. Chronicles in Plasticine.

From the notes, I don't believe any of them. A note from a hacker might be true, or it might not be; it's hard to tell. But the other two notes ("Monitoring Arcom yielded nothing. We should have had lunch instead" and "News from the plasticine fields: Ruddy didn't show up"), supposedly both from Willy Barankin, are definitely false. Because the note was written in the order of ND after the murders, so it definitely wasn't written by Shamrock.

Added 1 minute ago
Most likely, this is the mafia communicating with each other. And executing someone based on the notes would be very imprudent.