To answer a few posts here, which drifted into how to buy a sound surpresser & take it the same day,
This tragic incident reminded me of Marcus Wynn's 2002 novel; No Other Option. That plot is a lot like a Dormer.
A highly trained covert ops/SF soldier goes "off the rez" & tears across the midwest US. The rapist/murder is tracked by his close friend & fellow spec ops commando. Wynn is a highly trained security expert & former US special operations/FAA Sky Marshal.
I read another good novel in the mid 2000s with a storyline about 2 1st grade NYPD detectives who are forced to track down a retired NY State Police Captain. The retired cop is 62 but looks 32, has training & weapons and goes on a rampage when his son is murdered.
To my understanding, .50BMG is not allowed in CA by citizens. Barret Intl refused to sell or market .50 rifles & weapons to any CA law enforcement or public safety.
As for Willie's post, Dormer has a valid point but he's hardly worth any praise or admiration. He's a ruthless killer who preyed on unarmed citizens(some helpless women). He's scum and will burn for it.