COPENHAGEN, Denmark (AP) — Police in southern Sweden say they have found what they believe is the gun used to kill a woman in a suspected gang-related slaying which Prime Minister Stefan Lofven has called "an unbelievably cruel act."

The 31-year-old woman, who reportedly was carrying a child in her arms, was shot in the head Monday. Police say their main theory is that the child's father was the shooter's target. A man was arrested Monday, but he is not believed to be the gunman.

Senior police officer Mattias Sigfridsson said Tuesday "we have a good picture of people involved" in the shooting in Malmo, Sweden's third largest city.

Sigfridsson said Tuesday "it is far too early to draw any conclusions." He declined to elaborate.