tled  When Good Dreams Haunt You,  he describes a vivid dream where Graham, who he calls his  little brother Duke,  doesn't realize he's dead.

 Duke spoke about this supposed friend of ours being jealous of how good he was doing and didn't understand why. I started explaining to Duke that this comrade of ours was no longer a friend of ours, and that envy made him a monster I told him that person is only a shell of someone we onced [sic] love but no more,  he wrote.

 I told him between sobbing that the person we loved, though he no longer loved us, had him murdered. Between my profuse crying I told him I was sorry and I failed him as a Brother, but would never fail him again. 

Prior to killing Rivera, Soto vowed revenge during a recorded phone call with his twin sibling, Jonathan - also nicknamed  Twin  - who was locked up on Rikers Island, and two others, prosecutors said, presenting the audio to the jury.

 Trying to insult my intelligence like he don't know what he, like he care. Ain't shed a tear, ain't shed a mad nothing…. I got this s-, I got it. I ain't leaving until something happens,  he said, according to a transcript of the call filed by prosecutors in June.

His brother tried to calm him down, warning him,  Yo, chill. You can't, you can't really talk like that,  and  Just stop talking, be easy, man.