The Polk County Sheriff's Office said they arrested 4 people and retrieved about $3.5 million worth of fentanyl from an alleged drug trafficking organization operating in several states.PCSO said multiple agencies assisted in the investigation.PCSO said in August 2023, a task force began an investigation out of Mexico that specialized in fentanyl. During the early stages, investigators said two kilograms of fentanyl was delivered from the trafficker in Mexico to detectives.According to PCSO, a second delivery was coordinated, this time in-person, at a motel in Lakeland on April 5 for one kilogram of fentanyl.After the success of those transactions, the trafficking organization agreed to ship 11 more kilograms of fentanyl to Polk County.On April 22, detectives said Maria Machuca-Alderete, 29, Maria Guadalupe-Garcia, 48, Sergio Garcia, 52, Pedro Rodriguez-Correa, 31, arrived at a location in Polk County to deliver fentanyl and were arrested by deputies.Deputies said Rodriguez-Correa brought a 6-year-old boy with him to the delivery. The boy was taken into custody by the Florida Department of Children & Families.PCSO said multiple agencies assisted in the investigation. In total, 14 kilograms of fentanyl was seized by authorities. A fifth suspect involved in trafficking is still wanted.Deputies charged all 4 people with trafficking fentanyl over 28 grams and additional charges.