Marcus Wesson was brought into custody after walking out of his home, covered in the blood of his children, and then came his trial, during which he was faced with nine counts of murder, nine more of forced rape, and five of continued sexual abuse. Ultimately, he was found guilty on all of those counts of murder and rape, and he was subsequently sentenced to death. Since that trial, he's been sitting on death row at San Quentin.
It sounds like it would've been an easy case, but Marcus' lawyers actually tried to make the argument that he wasn't responsible. And there was actually something to their argument. Upon investigating the scene and, more specifically, the gun, it was discovered that his fingerprints and DNA weren't actually on the gun, nor was there any gunpowder residue on his hands. On the contrary, the DNA of his daughter, Sebhrenah Wesson, was found there (though there were still no fingerprints or residue). Taking that information, Marcus' defense tried to argue that Sebhrenah was actually the one to fire the gun, killing all of the kids before dying by suicide. Technically, forensics couldn't rule out that option entirely, and Sebhrenah had, in the past, shown a particular fascination for guns and weapons. But the argument didn't prove strong enough, with the prosecution pointing out that, even if he didn't pull the trigger, he had caused enough emotional and psychological damage to push his children to the point where they would commit murder.
