All of the Word of God[YHVH] is important; to live a Right-standing relationship with God and mankind. The Lord is very specific and patient in explaining His Rules. When we violate them it can separate us, and also loose evil spirits among us. Every manufacturer has an owner's Manual - including God. When in doubt, look to the Manuel.
T.M. case has been in the media for almost one year, and many Christians don't know which side of the fence that they should be on. We must control our emotions, and meditate on the Word, which allows for self defense for themselves and family. Let us look at the word murder in the Word.
Murder = Criminal homicide[Liv.35:16-20]. Unauthorized killing[Ex.20:13]. Laying in wait[ambush], or with hatred in the heart.
The Word allows protection against attacks, and states that the blood of the attacker, is on his own head if he dies during the attack. In the "Z" case, we only need to establish that someone was the aggressor/attacker, and what was his intent[hatred in his mind].
In many places in the Word, we must distinguish killing - from murder, by the context. Self defense is killing, and should be for the courts to decide; but the Ultimate Judge and the victim are standing by, with God as the Witness, and possible Executioner. There are No unsolved, or unresolved cases in Heaven; including abortion.
We are Not to kill the innocent or the righteous[Psalms10:8]. "Murder comes from the heart[Matt.15:19]." It comes out of anger[Matt.5:21,22]. Murder is the work of the flesh[Gal.5:9]. What is on trail? Christian Principles. Listen to man, leads to Idol worship. Rom.1:29-32 is our measuring stick; don't break these Rules, or have pleasure[consent with them] with those that do, break the Rules.