Alan Leroy McVay, 46, is charged with two counts of malicious destruction of property by explosion, the Medford Mail Tribune reported.
He pleaded not guilty Wednesday to both counts in U.S. District Court.
Investigators say McVay threw a small pipe bomb taped to a propane tank into the window of the district attorney's office early Nov. 13, causing little damage because it failed to explode.
The suspect was arrested Nov. 20 after police received a tip.
McVay allegedly told police he threw the bomb into the office in an attempt to avoid a Nov. 14 hearing and 36-month prison sentence for burglary and other charges.
A trial in the case has been scheduled for Feb. 11.
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