The prosecution is recommending a charge of Aggravated Homicide, which carries a minimum of 15 years. But it seems the judge has not yet made a finding as to whether to accept that charge. (Joran's lawyer says the preliminary investigation isn't complete and there's still some issue as to whether Joran was deprived a certified translator when he made his post-arrest statements.)

Here's how the insanity process works, as best as I can determine from the Pervuian code, using Google translator. (Scroll down to Articulo 75.)

Here's how the three murder statutes break down.

It seems to me Joran would first file a petition asserting temporary insanity with the court. The court would appoint experts and make a finding on Joran's mental state at the time of Flores' death. If the court agreed Joran was temporarily insane at the time, he would (as we say here) bind the case over for trial on the lesser charge of homicide violent emotion, rather than aggravated homicide. Only if he does so, it seems to me, could Joran plead guilty before trial and be assured of a 3 to 5 year sentence. If the judge rejects the temporary insanity claim, and determines the aggravated murder charge is appropriate, it doesn't seem like Joran would have the option to plead to the lesser crime of homicide by violent emotion.

Speculating about how criminal laws work in another country is a perilous endeavor. So I'll stop now. But I think what Joran's lawyer is saying is that he's asked the court to find Joran temporarily insane, and if the court agrees, so that Joran is facing only a homicide by violent emotion count, he'll plead guilty. Sounds like a long shot to me. But, he also may just be sending a signal to the judge that there's a way to resolve this case without spending years in litigation: Find Joran temporarily insane and bind him over on the lesser charge of murder by violent emotion, and Joran will plead guilty and accept the 3 to 5 year sentence.