Jens Christian (Kristian) Eggen is a Norwegian who first moved from the Trondheim-area (Namdalen?) to Kirkenes in the very north of Norway. A few years later he left Norway (1865?), heading for the US. I don't know anything else about him, but he gave name to a place near Kirkenes called Namdalen. I just wonder who was he, why didn't he just travel to the US instead of taking the tour to Kirkenes first? (that was a journey which took at least six weeks by boat at that time) Is there any family out there?
Quite a few Norwegians who later came to America first tried moving to the northern areas of Norway. It is impossible to know WHY Jens decided to take that step first - but we can speculate. The trip to America would cost money - perhaps Jens went further north to earn the money for that voyage? Perhaps Jens wanted to see if opportunities were better in the more sparsely occupied areas of his own country before facing a long dangerous trip across the ocean and a new strange country where he'd also have to learn a new language?
You may have to do study into the actual conditions around Jens in his earlier life to be able to make more informed speculations.
There are always questions that have no answers. As Hopkins advised, you have to research the external events around people's lives to try to reconstruct it.
The Trondheim police protocols do not start until 1867.
Are you looking for Jens in the U.S. If so, more information would be helpful, date of birth, where did he settle, family, etc.