The man who was shot dead was in his 25s.
He was found shot dead by a passer-by at lunchtime on a Friday in October last year.
The woman who is now arrested is the same age as the victim.
- But it is true that I requested a person arrested in the first place for probable cause for murder in Märsta on October 2 last year, prosecutor Rickard Wahlqvist told Expressen.