United States Attorney Alison J. Ramsdell has announced the sentencing of Guillermo Calderon, also known as “Memo,” a Rapid City man involved in a methamphetamine distribution conspiracy. U.S. District Court Judge Karen E. Schreier sentenced Calderon to 25 years in federal prison, followed by five years of supervised release, and imposed a $100 special assessment to the Federal Crime Victims Fund.
U.S. Attorney Ramsdell commented on the impact of methamphetamine in South Dakota communities, stating that “Calderon played a significant role in perpetuating this problem by trafficking methamphetamine into Rapid City and within the Pine Ridge Reservation.” She credited skilled federal and tribal law enforcement partners for their role in bringing Calderon to justice.
Special Agent in Charge Alvin M. Winston Sr. of FBI Minneapolis emphasized that Calderon’s operation brought “violence and addiction into vulnerable communities” through cartel-linked drugs. He assured continued collaboration among federal, state, local, and tribal partners to combat drug trafficking networks.
The investigation revealed that Calderon led a conspiracy distributing large quantities of methamphetamine sourced from Mexican cartel operatives into Pine Ridge and Rapid City. He employed firearms and threats throughout his distribution activities. Iowa law enforcement arrested him in January 2024 while transporting approximately 20 pounds of methamphetamine to South Dakota.
Judge Schreier highlighted Calderon’s culpability as the most violent member of the conspiracy during sentencing, noting that he distributed 100% pure methamphetamine from a Mexican cartel source.
The case was investigated by several agencies including the Oglala Sioux Tribe Department of Public Safety, Bureau of Indian Affairs, Drug Enforcement Administration, and FBI. Assistant U.S. Attorney Anna Lindrooth prosecuted the case.
Following his sentencing, Calderon was taken into custody by the U.S. Marshals Service.
