To get 2nd weapon,let barry check the dining room again then go upstairs and go to the 2 doors(do not go into the left side, instead,go to the right side then enter the door then go to your right you will see blood(it is forest's)then go inside the door ,you will see barry he will talk to you that he is investigating the cause of forest's death,he will tell you to leave and will give you the second weapon (BAZOOKA)find acid and explosive rounds for your BAZOOKA!! Then rule the mansion.