I dunno -- that execution shot to the back of the head of MM says RAGE to me.
But I also think PM found AM's pills that night and AM was on a mission to retrieve them from his murdered son's pocket.
He'd already made a deal with PM that he'd go to rehab after PM's criminal case settled and PM betrayed him by playing "little detective" for MM.
AM loved AM more than his family. JMO
Cold rage, though. To me rage is something that causes people to nearly black out (or black out) in a kind of frenzy. I've been asking tons of people about it, though. I'm pretty sure I've never experienced it.
People tell me that they have "gone into a rage" and punched a wall or hit a person, without any memory or consciousness of so doing, until the action results in the emotion subsiding. Road rage defendants or perpetrators often can give absolutely no account of why they did what they did, they just did it.
Cold fury (or cold rage) is more like seething. I'm capable of that, but even with seething, I've known people who are in that state (regarding some other person) for months, or years. We've had more than one person fired for cause from our college for attacking a colleague/another employee. These were professors and, well, one college president. I know the college president well. He's a seether, but he also told me that he has moments of "blind rage" (he doesn't remember lunging at the victims, or pounding on the table, or standing up with his fists clenched while screaming at an employee - I believe him, I've actually seen him do it, I just didn't figure he'd get all the way to fired for pounding on a table and knocking over a beverage container, among other similar incidents).
I think the shot to the head was coldly calculated and that he wanted her alive for the number of seconds it took him to tell her what he wanted to say - to complete his notion of personal justice and to make her absolutely as terrified and horrified and despairing as possible. I may be influenced by some other cases I've read about recently, but it did occur to me that he disabled her, put her down on the ground first. Surely she, like most mothers, thought she would run and intervene to save her son. She didn't have time to calculate what was going on, almost no one would be able to.
He blamed her for raising his loser, alcoholic, uncontrollable, felonious son - he didn't count on having a mini-me in the form of Paul. She was still sticking up for Paul, up until the end, and he was not having it. I wouldn't be surprised if he actually had the mindset of punishing her in exactly this way, which he had thought about frequently and coldly calculated.
Rage, to me, is a more immediate emotion that is a direct response to a specific circumstance - but if he was in a rage just minutes before (while dealing with the chicken), it didn't show - and I do understand that other people might think that he still could have been enraged for hours or days, but I find it hard to use the word that way.
Maybe we could call it habitual, controlled rage.
I think he's seething right now, btw. Intensely.
IMO.