Arresting Most Wanted Criminals will increase your hourly earnings significantly. But this could take some time, as well as it could condition your growth strategy. Try to accomplish all the quests given since they could give you some tips to grow faster, open the proper departments, and upgrade the proper units.
Upgrade those objects that will increase your money per hour, and don't forget to expand the proper coverage areas by tapping on the map icon (check if your departments could investigate the crimes detailed before you open a new coverage area) so you can receive more reports.
Upgrade those objects that will increase your money per hour, and don't forget to expand the proper coverage areas by tapping on the map icon (check if your departments could investigate the crimes detailed before you open a new coverage area) so you can receive more reports.