This dramatic CCTV footage shows the moments after Nathan Sumner attacked PC Lisa Bates with an axe on a Sheffield estate.
In the footage Sumner is seen entering the shop in just his shorts before smashing bottles and talking energetically with staff and customers.
Moments earlier the 36-year-old had attacked PC Bates as her and a colleague attended Sumner's flat.
The police officer suffered a fractured skull and lost a finger in the brutal attack.
Sumner was found guilty of GBH with intent and was today sentenced to serve 15 years at Rampton psychiatric hospital.