How does the author use foreshadowing in Perfect Chemistry?

In Chapter 34, Alex is arrested for the first time, placing him in a position to be even more dependent on his leaders in the Latino Bloods. This forces Alex to agree to a drug deal despite his hopes to avoid such dealings as a Blood. At the same time, Alex has been asking a great deal of questions about his father's death. This causes Hector, a leader in the bloods, to threaten his mother in order to force him to stop. Hector's act only makes Alex more curious about his father's killer, suggesting to him that Hector is protecting a fellow Blood. This situation not only foreshadows possible danger to Alex, but it also shows how deep in the Blood's he has sunk and how hard it will be for him to eventually leave.