FLORENCE, Ariz. — Pinal County authorities on Monday identified a man deported to Mexico as a suspect in the killing of two men who went missing in 2008 in a case known as “the septic tank murders.” Their dismembered bodies were found near Casa Grande in 2009 and 2014.

Fausto Negrete-Olivas, 43, was identified as the suspect and his brother Dionicio Negrete-Olivas, 48, is considered a person of interest for authorities, said sheriff’s department spokesman Mark Clark.

Victims Baltazar Lopez and Azaren Cordova, both 36, were last known to be in a pickup truck headed to Casa Grande when they were reported missing from Phoenix on April 27, 2008.

The truck was found abandoned and burned about a week later and one of the men’s bodies was found in a desert wash in 2009. The other was discovered inside a septic tank less than a mile away in 2014.

An axe or a machete was used to dismember the bodies, the county medical examiner said.

Authorities believe Lopez had been involved with a drug gang and was executed, and that Cordova was probably in the wrong place at the wrong time.

Fausto Negrete-Olivas was previously convicted of drug trafficking in Arizona, served prison time and was deported to Mexico following his 2013 release.

Authorities are unsure about the whereabouts of Dionicio Negrete-Olivas, Clark said.