Can Arslan, 52, fatally stabbed father-of-three Matthew Boorman 27 times on his front lawn in October, before forcing his way into the home of a second man, Peter Marsden, and knifing him eight times, a court has heard.
Arslan was about to be evicted from his property on Snowdonia Road, Walton Cardiff, near Tewkesbury, after allegedly subjecting his neighbours to years of verbal abuse and threats.
He first told police "the voice said to me to 'kill him'" at around 7.30pm, after the attack took place, and later said the voice belonged to his childhood teddy bear, Bristol Crown Court was told.
Arslan denies the murder of Mr Boorman on the grounds of diminished responsibility.