it's normal, when you kill someone with life value and it's reacted by the people around them, they will get angry and shout you wanted, then the moral will automatically drop to -200 so they attack you legally, you can restore negative points by running out of their sight for a while, using smoke bombs, distracting them or leaving the map area and then coming back however it doesn't restore the point where you killed the person. (If you want to restore the number of killed points back to normal you have to rescue many slaves in the orkinds cave/fishkinds temple/abomation nest/random on the map about charity donation events for the poor/random above map of chased girls rescue event/some crash areas need to be rescued or if you have money you can restore in black market for 10000sp and church for 70000-30000sp)
If you kill people without important quests you should leave that map avoid killing more people and morale drops to zero you will have to have scu or say 20+ to be able to outrun the soldiers on the map, but in battle, no one will help you..., (note that the church should only increase in value, not restore, unless you have no way to the city and the black market)