DEN89DTI02

The owner of the home built acft had purchased it from the builder. He possessed neither an FAA medical, nor a plt certificate, & had no previous flt time in this make & model of acft. He told a witness that he intended to taxi it (presumably for familiarization). Subsequently, the acft became airborne & remained within about 1/2 mi of the dep end of rwy 30. Witnesses observed it maneuvering erratically after takeoff. One witness believed the unqualified plt cross- controlled the acft with left rudder & rgt aileron; the witness said the acft nearly hit a hangar. Subsequently, after an apparent pwr reduction, the acft entered a stall/spin & crashed in a steep nose down attitude. A local CFI rprtd he had given the plt aprx 4 hrs of dual instruction during a previous 12 to 24 month period, but the plt had not shown interest in following a regular/structured program of instruction. During tests, cannabinoids were detected in the plt's urine, but none was found in his blood.