Prosecutors have dropped charges against three of seven people accused of organizing a dangerous criminal gang and planning to disrupt the 2008 Republican National Convention in St. Paul with a host of unorthodox tactics. The case, which focused on an anarchist group called the R.N.C. Welcoming Committee, was widely regarded as the marquee criminal prosecution to emerge from the convention.

The Ramsey County attorney’s office said Thursday that it was taking the action “in the interest of justice” and that it had mailed plea offers to the other four defendants.

Bruce Nestor, a lawyer for one of the three whose cases were dropped, Monica Bicking, wrote in an e-mail that the dismissals showed that “this was a political case from the beginning, using charges of terrorism and conspiracy to riot to try and justify the massive police presence and repression.”