Maybe I have to give up,still can't find the crossbow.I noticed a barricade in the courtyard outside,but got no way to open it.3 control panels can not remove that barricade. Maybe the crossbow is in there?
At last, I got the crossbow!IT is hidden so well,but is not good to use.It just for one shot,and the reload is quite slow.BUT the arrows will stick to the enemy's body is very real.The weapons I like in this game are the machine gun and military shotgun. Gatling gun is very powerful,but could not use much.