On Friday, July 30, a woman was shot to death at a beach on Notviken in Luleå.
Shortly afterwards, a 32-year-old man was arrested who was later arrested on suspicion of murder.
Two weeks ago, two more men were arrested.
The suspected men are linked to both a criminal network in Stockholm and Hells angels in Luleå.
Prosecutor Jonas Fjellström says that they now have a picture of what happened that Friday night.
- We think we have a sequence of events, then of course you are always interested in clarifying different parts, says Jonas Fjellström.
Quantities of data must be analyzed
A major investigation is now underway by findings being sent to NFC, the National Forensic Center, and mobile masts have been emptied to clarify which people have moved on the site.
The inquiry has received help from other regions, mainly Stockholm, and now analysts are working to review all the data collected.
However, the prosecutor does not want to go into whether they have found any murder weapon.
- I can not say that.
We have made findings that we believe may be of interest for investigation, says Jonas Fjellström.