As the Woodstock ’99 concert ended last July in Rome, N.Y., in a rampage of fires, looting and generalized mayhem, Gregory Amoroso was a little surprised to find himself standing in the middle of it.

Amoroso, Rome’s 32-year-old corporation counsel, had been heavily involved in the planning for the concert, held over three days at the former Griffiss Air Force Base. But he had not expected to be touring the scene with undercover police officers when the event degenerated into rioting.