A 23-year-old man has been charged with the murder of Samantha Gosney, police said.
Officers launched a manhunt after Ms Gosney, 29, was stabbed multiple times at an address in St Helens on Saturday.
Adam Brettle, of no fixed address, was charged on Tuesday evening and will appear before magistrates in Liverpool on Wednesday.
Officers were called to a report of an assault at a house in Swan Avenue, Derbyshire Hill, at 11.40am on Saturday.
Ms Gosney was pronounced dead at the scene a short time later.
No further action will be taken against a 43-year-old woman from Warrington, a 45-year-old man from Warrington and a 67-year-old woman from St Helens who were earlier arrested on suspicion of assisting an offender.