I was never involved with the cases in any way.  But I know 3 (retired) investigators who worked it and two of them agree on 3 names (direct involvement), the third agrees with 2 out of 3 names, doubts the third.  One big remark:  they discount the generally accepted theory that it were always the same perpetrators behind all the facts.  And no, I'm not going to name their 'candidates', it's their theory, not mine and I certainly don't have the same level of knowledge as they had so am in no position to judge.  2 out of three suspects regularly appear in the public discussions, the third person is not generally known as a suspect.