The jury returned a guilty verdict in 3 hours.

I believe that drug addiction muddled Murdaugh's brain to the point that he had no idea how much evidence he was leaving behind. See the first post. Arrogance is a common symptom of drug abuse. Also:

the hired hand testified that somebody had run the hose the day of the murders, had left puddles in strange places, and had hung the hose up wrong. Outsiders wouldn't have done that. It was probably done by Murdaugh, cleaning himself up.   

casings were found around his property which matched those that shot Maggie, proving that she was shot with a Murdaugh family gun, not by outsiders.

Paul's friend Will Loving testified that he had been shooting with the murder weapon (supposedly lost somehow) in Dec. 2020.

Murdaugh's phone had 73 deleted messages the day of the crime

His car was documented by OnStar.

The clothes he wore before the shooting have disappeared. His son had made a video of him wearing them and sent the video to a friend.

Enough. Murdaugh's ravaged brain was no longer up to coping with a trial like this.

The Guardian commented, "No weapon, no confession, no motive." That's obsolete. If you're hip enough, your electronics will convict you.