The man suspected of murdering Linzi Ashton was already wanted by police on suspicious of raping her, Greater Manchester Police said.
Ashton accused Michael Cope of rape in April and Superintendent Kevin Mulligan said police had been seeking to arrest him since then.
Mother-of-two Ashton, 25, was found dead at her Salford home on Saturday.
More top news
The so-called Islamic State group has released a video, which purportedly features a British boy, appearing to execute a prisoner.
The two-year-old's condition is said to be "life-threatening" after he was struck by a car while out walking with his grandfather in London.
Lord O'Donnell, who used to head up the Civil Service, says he believes Britain may not actually exit the European Union.