My guess us that brother Randy was the smart one in the family, the one with the legal skills and professional demeanor. AM and JMM didn’t have those skills, but JMM was wise enough to go into a different line of business.
But not AM. He has been described as lazy, undisciplined, not a great lawyer but yet a great ‘producer‘, a great generator of income to the firm. I think that’s because these days, many cases are win not on the law per se but on emotion. Make the jury cry, make them furious…and you win…sometimes despite wrongdoing on the ‘victim’s’ part.
This is where AM excelled. Manipulating emotions. That’s how he became a big producer of revenue for the firm. AM also seemed to view other humans only as how they offered value to him.
So now…facing ruin, he realizes Daddy would be both unable to help him, but also, he’d be appalled… if he lived long enough to find out he‘d been stealing from the family firm. AM realized he could only rely on his own skill set. He needed something HUGE to distract, create sympathy, give him time. He needed to manipulate on a grans scale like he’d never done before.
And, as he mulled over his bombshell murder solution, I’m sure he justified it to himself. Poor Paul was probably going to jail anyway. MM would be miserable if he was ruined…both financially demeaned and socially disgraced. She’d never be happy that way. Better that HE survive to take care of BM and save the Murdaugh name.
This is how the prosecution case looks to me anyway. I hope it does to the jury as well.