For the first time, Peruvian officials have publicly identified the Shining Path guerrilla group’s military commander, Orlando Alejandro Borda Casafranca. The region where the group operates, Valley of the Apurimac, has become Peru’s largest producer of cocaine, which officials believe has helped fuel a resurgence of guerrilla violence in recent months.

Few details are known about Mr. Borda-Casafranca, 42, who allegedly disappeared in a remote jungle region while still a teenager. What little is known, including the identity of his family, was provided by two Shining Path members who deserted earlier this year and have been cooperating with federal authorities.

The Shining Path is Peru’s most infamous terrorist group, whose actions are believed to be responsible for at least half of the 69,000 people estimated killed in violence that occurred from 1990 to 2000. An estimated 40 Peruvian soldiers have been killed in recent months with the resurgence the Apurimac region.