Angelo's Stand ability was brought forth by the mysterious bow and arrow, and apparently they're also connected to DIO. After defeating Angelo, Jotaro thought that the danger had left the city, and tries to find the whereabouts of the bow and arrow. A few days later, Koichi is walking home with Josuke, and they pass a house that should be empty...
The bow and arrow that 
Angelo was talking about...
...القوس والسّهم اللّذان كان أنجيلو يتحدّثُ عنهما
Der Pfeil und Bogen,
von denen Angelo gesprochen hat …
Angelo a parlé
d’un arc et d’une flèche.
L'arco e la freccia menzionati da Angelo...
Angelo mencionou um arco e flecha...