Trayvon Martin was not "poor". Both parents were working. From his wiki:
"Martin was born in 1995 in Miami, Florida, to Sybrina Fulton and Tracy Martin, who divorced in 1999. At the time of the shooting, Fulton was a program coordinator for the Miami Dade Housing Authority, and Tracy Martin was a truck driver; they lived near each other in Miami Gardens. Martin's older maternal half-brother, Jahavaris Fulton, was a college student at the time (who would later testify in the Zimmerman trial)"
Trayvon was middle-class, or upper working-class, but still a thug.
the point was not that the police check their bank balance before deciding to be ruff with them. It’s that poor people of any color are far more likely to look dangerous or scary. But rich people can look ruff too sometimes. And wearing a hoodie with the hood up while creeping around other peoples houses at night is the same as being a poor thug, you LOOK like a poor creepy/dangerous thug.