Sheila Nolan heads a criminal gang hijacking trucks and relieving them of their cargo. She was depicted in a 1959 episode of 'Highway Patrol' called Cargo Hijack (Season 4:28) by actress Cathy Case (aka Kathleen Case: b.1933 - d.1979).
Sheila is married to Vance Nolan, of Nolan Imports. It appears that the marriage was mostly a business arrangement with Sheila as the mastermind. Her scheme involves hijacking cargo trucks and selling the shipments on the black market through Vance's front-company.
She plans the operations, manages the henchmen and oversees the hijacking. With her shapely figure and tight business-suits, a lot of motorists probably passed by without noticing her henchmen pulling the caper! Things get complicated when Vance shoots a driver and Inspector Matthews gets involved. He puts a stakeout on cargo shipments, but the wily Sheila stages a fake hijacking to throw him off the scent.
Inspector Matthews, though, isn't easily fooled---and tracks the gang to their hideout. Sheila and her men slip through their fingers, split up and escape. Matthews captures two of her men who confess where Vance and Sheila have fled to save their own skins. Matthews tracks the two to a warehouse when Vance decides on a shootout and goes down in a hail of police gunfire.
Angrily complaining about the stupidity of her men; the defeated beauty emerges with her hands up, which a patrolman firmly pulls behind her back and into handcuffs.
"What's going to happen to me?" Sheila moans.
"Look what happened to him." Matthews points to her deceased husband, then walks the handcuffed villainess away to her punishment.