Before Beheading, Attacker Asked for Large Knife Store owner threw him out, but didn't report threat By Evann Gastaldo, Newser Staff Posted May 16, 2011 10:50 AM CDT 15 comments Comments Deyan Valentinov Deyanov is caught on a supermarket security camera gesturing to show the size of knife he wants. (drewbarliona) (Newser) – Another tragic twist in the Tenerife beheading story: Before the attack, Deyan Valentinov Deyanov asked a store owner for a large knife because, he said, "I'm going to kill someone." But the shopkeeper didn't report the threat to police. Deyanov was caught on the store's security camera gesturing with his arms to show what size knife he wanted. He even ran his finger across his throat to demonstrate his plans, the Telegraph reports. The store owner threw him out, but within half an hour, Deyanov had followed Jennifer Mills-Westley into another store, grabbed a knife off the shelf, and decapitated her in an attack involving at least 14 blows of the knife. Locals say Deyanov, who became more aggressive after breaking up with his girlfriend recently, told police in February that he was "planning something big." He had previously attacked a security guard, knocking out three of his teeth. Click to read about Mills-Westley's plea for help before the attack.