Meas Muth is allegedly the head of the Khmer Rouge navy. And the Cambodian investigating judge decides that he’s not senior enough to be sent to trial.
Cambodian judge:
“His position and roles are much more in line with facilitation, and not active participation in policy-making...His participation was neither proximate to nor active in the commission of the crimes.”
“His position and roles are much more in line with facilitation, and not active participation in policy-making...His participation was neither proximate to nor active in the commission of the crimes.”
”The National Co-Investigating Judge concluded that the ECCC does not have personal jurisdiction over MEAS Muth and dismissed all allegations against him accordingly.”
Compared to the international investigating judge: “Both the position &conduct of Meas Muth mark him out as a major player in the DK structure &as a willing &driven participant in the brutal implementation of its criminal & inhuman policies. He should stand trial for his crimes.” 
This case is politically sensitive. Strongman PM Hun Sen has said for years that he didn’t want Muth’s case to go forward and that if it did, civil war would break out.
