A man who murdered a lone mother-of-two in her Lancashire home as her infant child slept upstairs rapped about killing someone just an hour before the attack, police said.

Anthony Stinson, 31, came across Charlotte Wilcock on the evening of March 3 as she smoked a cigarette on her doorstep in Primrose Terrace, Blackburn, before kicking her and stabbing her to death with a Stanley knife in her hallway.

Ms Wilcock’s 15-month-old daughter was left alone upstairs until police officers discovered her the next day.

The 31-year-old mother, who did not know Stinson, was found dead behind her front door.

When police arrested him, Stinson, of Queen Victoria Street, Blackburn, said he had been suffering from psychosis when he attacked Ms Wilcock and claimed to have seen the Devil.

But when detectives searched his phone, they found that he and a friend had made a rap video which described killing someone just an hour before the unprovoked attack.

CCTV footage also showed that just 15 minutes earlier, he made conversation with a local shopkeeper while buying alcohol and cigarettes.

Stinson pleaded guilty to Ms Wilcock’s murder at Preston Crown Court on Monday and will be sentenced on Thursday.

Speaking outside of court, detective chief inspector Mark Haworth-Oates, of Lancashire Police, said: “On March 3 this year Stinson approached Charlotte’s address and, for reasons known only to him, launched a brutal attack on her on the doorstep.

“He slashed at her body numerous times in the ferocious assault – inflicting well over 50 individual injuries in the process, many with the use of a Stanley knife – as well as punching and kicking her.

“Charlotte had never met Stinson before that night and had no personal connection to him – she was merely sat on her own doorstep having a cigarette.

“She should have been safe and could never have foreseen what was about to happen.

“It is clear from speaking to Charlotte’s family that she was very much-loved, and her death has left a huge void in the lives of those who knew her, not least her two children who will now grow up without their mother.

“It is such a needless loss of a life in truly awful circumstances.”