©2020 Inmate Lookup Jefferson County CO. Number: IS03 Inmate Search will search in real time for inmates of the Jefferson County jail. Once an inmate is processed their details will be available for search. If you are unable to find the inmate you are looking for please double check spelling. Inmate Search will search in real time for inmates of the Jefferson County jail. Once an inmate is processed their details will be available for search. If you are unable to find the inmate you are looking for please double check spelling.