OTTUMWA — A three-year-long investigation has resulted in four convictions on federal drug trafficking charges.

Lt. Tom McAndrew of the Ottumwa Police Department announced the convictions Wednesday. Hector Avila-Luna and Sandra Campos-Gomez ran an Ottumwa methamphetamine and marijuana ring with ties to a larger organization based in California.

Both pleaded guilty to conspiracy to distribute 500 grams or more of a mixture containing methampehtamine and 50 grams or more of meth, along with 50 kilograms or more of marijuana. Avila-Luna received a life sentence. Campos-Gomez will spend 12 years 7 months in prison.

Investigators purchased 474 grams of meth and 241 grams of cocaine from Inocencio Hernandez-Atica and Francisca Imelda-Rubio during the investigation. The purchases totaled more than $26,000 and both dealers were arrested after they delivered the drugs.

Hernandez-Atica and Imelda-Rubio also pleaded guilty to possession of 50 grams or more of methamphetamine with intent to distribute. Hernandez-Atica will spend 4 years 3 months in prison, while Imelda-Rubio received an 18-month sentence.

The investigation involved multiple agencies in and around Wapello County.