How does the author use foreshadowing in Scorpions?

The gun is the primary motivator in the story. It is never established how Mack has a gun to give Jamal. Mack gives the gun to Jamal when he is trying to convince Jamal to take over the leadership of the Scorpions. Tito is afraid of the gun and voices his fear from the beginning. His concerns foreshadow the sad consequences of his actions. It seems unlikely from the beginning that Tito would be the one to use the gun, but his friendship for Jamal spurs him to use it to defend him. The gun hangs ominously over the boys from the minute they take possession of it.