COLORADO SPRINGS, Colo. -

The District Attorney's Office called the Sheriff's Office's actions during its investigation in the murder of Department of Corrections chief a "mystery."

Prisons' Chief Tom Clements was murdered at his Monument home in March 2013. Since then, investigators with the El Paso County Sheriff's Office have been investigating this case.

Investigators believe parolee Evan Ebel pulled the trigger. Ebel was a known member of the 2-11 crew, a white supremacist prison gang. Investigators do not believe Ebel acted alone.

El Paso County Sheriff's Office spokesperson Jeff Kramer said during the first year of the investigation, investigators have had "conversations" with the District Attorney's Office.

"(Investigators) provided information concerning alleged activities of co-conspirators in the Clements case. During those conversations, the DA’s Office stated they did not believe there was enough evidence to pursue charges," said Kramer.

Spokesperson Lee Richards with the 4th Judicial District Attorney responded with this statement to KRDO NewsChannel 13.

"From March 19, 2013, we have had a team of experienced prosecutors, including District Attorney Dan May, committed to this investigation. As a part of this commitment, the District Attorney’s Office has repeatedly requested reports from the El Paso County Sheriff’s Office in order that we may be advised of any progress made in their investigation. Again, no reports have ever been provided," said Richards. "The motivation behind the recent allegations made by the El Paso County Sheriff’s Office remains a mystery."

Kramer said the Sheriff's Office has not requested prosecutors file charges against alleged co-conspirators in the case. Richards also said the Sheriff's Office has not presented any reports to District Attorney's Office.