From the Feb. 27, 1908 NYT:

A $12,000 pearl and diamond necklace was reported to have been lost this afternoon in Poinciana Garden, and a $500 reward was this evening offered for its return to "Frank of New York."

There seems to be a good deal of mystery about the affair.

I wonder how that worked out. Perhaps it was not advisable to advertise the value of the necklace along with the substantially lower reward.

The alias might have been an attempt to avoid a black-mail situation, but revealing the value of the necklace [about $270,000 in 2006 dollars] would seem to have invited whoever has the necklace to ask for a higher reward or to fence the item at a value between $12,000 and $500.