根据维基，只有联邦系统才所有重罪都经过大陪审团。各个州有自己的搞法，目前只有一半的州使用大陪审团：
The federal government is required to use grand juries for all felonies, though not misdemeanors, by the Fifth Amendment to the United States Constitution. While all states in the U.S. currently have provisions for grand juries,[3] only half of the states actually employ them[4] and twenty-two require their use, to varying extents.[5] The modern trend is to use an adversarial preliminary hearing before a trial court judge, rather than grand jury, in the screening role of determining whether there is evidence establishing probable cause that a defendant committed a serious felony before that defendant is required to go to trial and risk a conviction on those charges.
管刘强东案的明尼苏达州Hennepin的大陪审团只管杀人案（所以不会管刘案）：
Minnesota
Hennepin County, Minnesota (which contains Minneapolis) keeps a grand jury impaneled at all times. Each grand jury serves a term of four months, typically meets one day each week, and focuses almost exclusively on homicide cases.
检察官说服大陪审团其实很容易：
New York Judge Sol Wachtler once famously said that a grand jury would “indict a ham sandwich.”