I don't feel sorry for him in the slightest. Not only did he murder Christian in the most horrific way possible, he outlined a plan (fanciful it may have been, but the intent was 100% serious) whereby at least four more people/students would have to be randomly murdered so he could save his sorry skin.
On top of that, and in the face of overwhelming evidence to the contrary he sat in that witness box and lied for several hours. Patently obvious, farcical, ridiculous lies - in fact, his lying testimony was the only defence they could muster. Not a single character witness, not a friend, no-one to speak for him, no experts to attempt to contradict the forensic evidence, nothing. Just Pedro's sociopathic arrogance as he sat there and lied and lied, insulting the intelligence of everyone in that courtroom and everyone watching at home. Every sentence he uttered just reinforced his guilt.
Then, having been found guilty on all counts by a jury that took only three hours to decide (including dinner!) - did he admit his guilt, ask forgiveness, show real remorse and genuine contrition? Nope - he stood there and pronounced his innocence. Even now, even in the face of indisputable and insurmountable evidence, with nothing to contradict it, other than his lies .. he still claims he is innocent. If he were willing to face up to what he had done that would be something, but he doesn't.
So no, I don't feel sorry for him. Not even a flicker of pity. The way in which he killed Christian - the premeditation, the sheer horror of the act itself, and what he did in the aftermath of the killing .... is all the proof I need that he is evil to the core. And as for him not being 'smart' - he's a highly intelligent young man, just nowhere near as clever as he thinks he is, and he has been outwitted at every turn by fine police work, a first class prosecution team, excellent witnesses and the courage and dignity of Christian's family.