AFTER RETURNING FM A LOCAL NGT FLT, THE ACFT WAS LNDD GEAR UP WHEN THE LNDG GEAR DID NOT EXTEND. THE ACFT BGN BURNING AFTER IT CAME TO REST. IT WAS EXTENSIVELY DAMAGED BY FIRE & THE CAUSE OF THE GEAR MALFUNCTION WAS NOT DETERMINED. LOCAL POLICE, WHO RESPONDED TO THE ACCIDENT, NOTED 'AN ODOR, COMMONLY ASSOCIATED WITH ALCOHOLIC BEVERAGES' COMING FM THE PLT. HE WAS REMINDED OF THE GEORGIA IMPLIED CONSENT WARNING, BUT REFUSED TO PROVIDE A BLOOD SAMPLE FOR THE POLICE TO USE FOR A TOXICOLOGY TEST. AN INVESTIGATION REVEALED THE PLT HAD ONLY A STUDENT LICENSE & HAD TAKEN THE ACFT WITHOUT THE OWNER'SPERMISSION. THE OWNER WAS AN ASSOCIATE OF THE PLT'S UNCLE. ONE OF THE PASSENGERS STATED THAT HE & THE PLT HAD BEEN 'DRINKING' & THEY DECIDED TO GO FLYING WITH 2 OTHER PERSONS. HE NOTED THAT WHEN THE GEAR DID NOT EXTEND, HE SAW A RED HANDLE THAT SAID 'EMERGENCY GEAR DOWN.' HE STATED 'I STARTED TO MESS WITH IT, BUT IT DID NOT DO ANY GOOD.' THE PLT STATED THE GEAR DID NOT EXTEND BY USING EITHER THE NORMAL OR MANUAL SYS. HE RPRTD ONLY 2 HRS FLT TIME IN PA-24 ACFT.