Yup, and it's the very definition of a Hail Mary. This isn't some guy who just pulled out a gun and shot someone. He spent weeks, if not months planning this. He obtained fake identification, built not only a gun, but a silencer as well. He wore a mask, stayed a hostel to minimize his exposure, calculated his movements to avoid detection, stalked his victim, and planned and executed not only the murder, but exactly what he would do after (escape).
Did he know what he was doing? LOL, without question.
Did he know it was wrong? Again, LOL. Hence all the subterfuge and his own words, which indicate as much. All I can say to his attorney is "good fricken luck with that."