|Ethel Janowski (Alden) has a lot of problems on her..uh, plate.
Weighing in at a whopping 250 pounds, she could stand to cut back on her food intake. But that doesn't seem likely.
She's also mentally unstable, and is currently receiving electroshock therapy. She lives with her grandmother (Lambert) and has no social life.
So, when grandma locks up the grub in an attempt to send her portly granddaughter a helpful hint...Well, all it does is push Ethel over the edge! She kills her grandmum and stores the body in an upstairs bedroom. But it ain't over 'til the fat lady bares her cleaver.
Ethel continues her feverish killing spree, hacking up anybody and everybody that comes a-callin'!
The good news is that Criminally Insane doesn't treat it's kooky premise as a parody, and instead chooses to play it as a straight psychological horror. (Think of it as Repulsion for the obese set.)
It doesn't try to be a comedy, and therefore avoids the pitfall of becoming another Microwave Massacre (1979). Alden is remotely interesting to watch, and plays Ethel as the withdrawn mess that she's become.
The bad news is that Criminally Insane never really takes off.
There's no background provided on Ethel, so her homicidal tendencies don't have any focal point. The murders have no real buildup, and seem like they're just violent reflexes from crazy Ethel. Horror addicts are the only ones who won't find this a complete waste of time.
Followed by a sequel, Criminally Insane 2, in 1987.