Sheriff Keith Nygren called the suspects "dangerous people" who robbed businesses at gunpoint.
Investigators got a break earlier this month when they arrested five people after an attempted robbery in Vernon Hills.
"The attempted robbery was foiled when members of the McHenry County sheriff's police sprang into action and thwarted the offenders by breaking through a glass door and rescuing two of the victims," said Nygren.
Nygren said officers from the sheriff's department, several suburbs and the U.S. Marshal's Office were involved in the investigation.