SPRINGFIELD-Two inmates at Mike Durfee State Prison in Springfield were charged with drug possession last week.

Jonathan Gundvaldson, 32, faces a Class 6 felony charge for allegedly possessing synthetic marijuana while incarcerated on Sept. 7. Anthony Pewo, 32, is charged with the Class 4 felony of possessing marijuana while in prison on Oct. 11.

The separate indictments, both filed on May 9, do not indicate that the alleged offenses were related.

Habitual offender information was filed in both cases, indicating that each man has previously been convicted of five felonies.

That information states that between 2008 and 2012, Gundvaldson was convicted of first-degree burglary twice, as well as for grand theft and two drug-related offenses, all in Minnehaha and Lincoln counties.

Pewo is said to have been convicted of vehicular homicide, simple assault against a law enforcement officer, forgery and third- and fourth-offense DUIs between 2009 and 2013. His convictions are from Brookings, Moody and Union counties.

While the charge of being a habitual offender convicted of three or more prior crimes of violence does not carry a sentence of its own, it could enhance the sentence for the other felony charges to that of a Class C felony, which is punishable by a maximum of life in prison.