Kate Doyle of the National Security Archive and the Open Society Justice Initiative's riosmontt-trial.org has the most accurate summary I've found of today's confusing and widely mis-reported legal developments in the Guatemala genocide trial of General Rios Montt and former head of intelligence Jose Mauricio Rodriguez Sanchez:
Today the Constitutional Court sowed chaos and confusion in a trial that last Friday (April 19) was probably two or three days away from its conclusion. The only steps remaining were hearing the testimony of whatever remaining witnesses the defense could muster, and hearing the closing arguments of prosecution and defense lawyers.
It is impossible to summarize accurately what happened without having access to the Constitutional Court (CC) decision. (It should be available tonight.) The first press conference held by the CC today was so incoherent that the press complained and they had to convene a second one. Two important things will happen tomorrow that will help clarify matters: CALDH will hold a press conference at 10am to explain how they plan to respond to the latest developments, and the Attorney General’s office will make some kind of statement to the same effect.
Meanwhile what I understand from reading the press, Twitter posts, messages from the new OSJI monitor Lisa Laplante, and emails from some of the stakeholders is the following: