The refuse left behind, like home COVID test kits, are items that the robbers did not want or did not think were valuable enough to take
https://www.dailywire.com/news/union-pacific-official-blames-l-a-s-far-left-policies-for-massive-train-thefts-considers-leaving-l-a
https://www.dailywire.com/news/union-pacific-official-blames-l-a-s-far-left-policies-for-massive-train-thefts-considers-leaving-l-a