▁more ▁than ▁two ▁dozen ▁U . S . ▁citizens , ▁who ▁had ▁been ▁det ained ▁for ▁periods ▁r anging ▁from ▁one ▁day ▁to ▁over ▁three ▁years . ▁Some ▁of ▁the ▁wrong fully ▁det ained ▁U . S . ▁citizens ▁had ▁been ▁arrested ▁by ▁I CE ▁more ▁than ▁once . ▁The ▁in ac cur ate ▁government ▁data ▁that ▁I CE ▁used ▁had ▁shown ▁that ▁both ▁imm igr ants ▁and ▁U . S . ▁citizens ▁were ▁both ▁targets ▁of ▁being ▁det ained . ▁In ▁ 2 0 1 9 , ▁a ▁U . S . ▁citiz en ▁that ▁was ▁det ained ▁stated ▁that ▁he ▁lost ▁ 2 6 ▁pounds ▁from ▁the ▁hor rend ous ▁conditions ▁that ▁the ▁det ention ▁center ▁offered . ▁ ▁San ctu ary ▁cities ▁ ▁San ctu ary ▁cities ▁are ▁cities ▁that ▁limit ▁their ▁co operation ▁with ▁I CE . ▁When ▁a ▁person ▁is ▁arrested , ▁his ▁or ▁her ▁information ▁is ▁placed ▁into ▁a ▁federal ▁database ▁that ▁I CE ▁can ▁access . ▁In ▁a ▁non - san ctu ary ▁city , ▁I CE ▁can ▁ask ▁the ▁police ▁to ▁hold ▁the ▁illegal ▁imm igr ant ▁until ▁they ▁can ▁pick ▁him ▁or ▁her ▁up . ▁However , ▁san ctu ary ▁cities ▁believe ▁this ▁is ▁un const itution al ▁and ▁view ▁being ▁an ▁illegal ▁imm igr ant ▁as ▁not ▁a ▁crime ▁but ▁a ▁civil ▁viol ation . ▁As ▁such , ▁the ▁top ▁officials ▁of ▁san ctu ary ▁cities ▁prevent ▁the ▁police ▁from ▁holding ▁an ▁illegal ▁imm igr ant ▁for ▁being ▁und ocument ed ▁by ▁policy