Mr Cameron, who was accompanied by Home Secretary Theresa May, visited West Cumberland Hospital, then Workington police station to pay tribute to staff who dealt with the aftermath of the shootings.
During their private visit to the hospital, the PM and Home Secretary met some of the victims who are being treated.
The PM then headed for the police station, where he was greeted by Chief Constable Craig Mackey.
They were briefed by senior officers on developments in the wide-ranging investigation and met some of those who were first on the scenes of the shootings on Wednesday.
During the visit the PM described the events this week as “the most appalling random acts”.
Obviously, people here in west Cumbria have suffered the most appalling tragedy and it will have a huge impact on the community.
And I wanted to come here to show (that) the Government wanted to listen, wanted to show how much it cares about what has happened here.
People - I have met some of them - are having to come to terms with the most appalling random acts that they will find very difficult to understand and in some cases there will be no proper explanation.
The PM also thanked the emergency services involved and the “incredible stories of bravery” from communities in Cumbria.
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