If Erle Stanley Gardner was still alive and writing his wonderful Perry Mason mystery series, he'd probably call this one the 'Case of the Missing Tombstone.' Mason would have his top private investigator, Paul Drake, out combing San Fernando Valley cemeteries for leads, while Della Street worked the phones back in the office lining up witnesses for the trial we all knew Perry would win in an hour, minus the TV commercials. But Erle and Perry are long gone so I'm turning to all you amateur sleuths and budding genealogists to help me out today. Here's what we got to work with so far: A few months ago, David Minas shows up for work at his Woodland Hills real estate development company, and his gardener comes running up to him. 'David, David, come look at this,' the gardener says. Stuck out back between a large trash container and concrete wall in the parking lot -- standing straight up -- is a tombstone for one James Sutton, born 1835, died 1907. It stands about three feet high, two feet wide, eight inches thick, and weighs at least 500 pounds, which means our suspect is either one incredibly strong man or had some help. On the face of the granite tombstone is etched -- 'At Rest. James Sutton 1835-1907. A pioneer.' A property manager by trade, Minas did the only thing he could think of. He called the cops. A couple of officers from the West Valley Division showed up, scratched their heads, told Minas this is the first stolen tombstone report they had ever taken, and left an hour later. 'If no one claims it in 45 days, it's yours,' Minas says one of the officers told him. Gee, thanks. The ideal Christmas gift. A 500 pound tombstone of a man who died more than 100 years ago. Nice conversation piece for the living room. 'I don't want it,' Minas says. 'I'm hoping someone in his family reads your column and realizes great-granddad's tombstone is missing, and they want it back.' Minas and his brother, Mark, did some sleuthing on their own, calling around to local cemeteries to see if they had noticed any of their tombstones missing. He even called the old Pioneer Cemetery in Sylmar, one of the Valley's oldest burial places, but they didn't have a complete list of everyone buried there up to 1929 when the cemetery stopped taking new clients. LAPD's Mission Division, which includes the cemetery boundaries, was briefed at roll call a few weeks ago about the found tombstone, but no one's reported Sutton missing. I called the Southern California Genealogy Society, which has lists of people buried in half a dozen local cemeteries, but no James Sutton born in 1835. 'I thought maybe it was all a prank, but why would someone dump a 500 pound tombstone out back by my Dumpster?' Minas wonders. 'They'd need a tow truck to get it in.' So, that's where we stand in the 'Case of the Missing Tombstone' -- at a dead end unless we catch a lucky break. What would Perry Mason do next? If you have any ideas, give Minas a call at his office 818-884-6167. 