He Got “Jumped In” At Age 10, Meaning Every Member In his Gang, Beat Him Up For 30 Seconds.
Getting “jumped in” to a gang is a common ritual for gang initiation. Other forms of initiation include being “sexed in” (a female member must have sex with all the male members of the gang) and the “Blood in- Blood out” rule (which means that you have to kill someone to get in and die to get out).