Missouri sword slayer suspect smiles for mugshot after allegedly killing boyfriend

Brittany Wilson was captured grinning in her mugshot after allegedly stabbing her boyfriend to death with a sword. Photo / Cape Girardeau Police Department

A US woman was captured smiling ear to ear in her mugshot after allegedly stabbing her boyfriend to death with a sword.

Missouri police were sent to Brittany Wilson's home last Friday after receiving reports of "suspicious activity" - but when they arrived at the scene Wilson's boyfriend was dead, Cape Girardeau Police Department said.

Wilson's partner, Harrison Foster, who lived with her, was found just after 11pm with "fresh stab wounds" on his body, according to police.

Wilson, 32, was arrested and charged with first-degree murder and armed criminal action.

During the emergency call she made to police, Wilson admitted killing her boyfriend with a sword.

Brittany Wilson was captured grinning in her mugshot after allegedly stabbing her boyfriend to death with a sword. Photo / Cape Girardeau Police Department

But it was her antics during her mugshot that caused even further outrage.

In the mugshot released by police, an orange jumpsuit-clad Wilson wore a wide smile.

Wilson had confessed to authorities that she and Foster had taken methamphetamines earlier on Friday, according to the CBS station and NBC affiliate WFLA-18, citing officers and police.

Wilson claimed Foster had "several other entities living inside his body for the past several months" and so by fatally stabbing him, she was "setting him free", the NBC station said, citing police.