This weekend, Deputy Chief of Police Mats Löfving stated that there are about 40 family-based criminal networks in Sweden - a statement that attracted attention.
In Uppsala, the police survey shows that there are two or three such networks.
The criminal clans have branches to Västerås, Gävle, Stockholm - and Malmö.
- They have relatives there and many are very mobile, which means that when there is a shooting in a family clan in Uppsala, they can gather strength and suddenly be up to 100 people.
Then the conflicts risk escalating, says Stefan Siesing, external officer at Uppsala Police.
Wants to stop the shootings
That is why it is important to stop the shootings, he says.
- We do this by constantly working in these areas, stopping vehicles and digging in pockets.
Then we can find weapons and we think that every weapon we take, we may prevent a fatal shooting or an assassination attempt, says Stefan Siesing.
Hear Stefan Siesing tell more in the clip above.