In the authorised continuation short story Miss Marple's Christmas, Bertie Finch is the under-gardener at Gossington Hall, hired because the gardener Collins had become too old for heavy lifting. Bertie is also the boyfriend of the second housemaid Dorcas.
Bertie became implicated in the loss of Mrs Esmé Dashwood's pearl necklace after Constable Palk found that a trowel had been used to force open the window in the boot-room and a trowel with flecks of paint was found in the potting shed. Finch's case was not helped by his background: the nephew of the baker in Market Basing, Finch had once served two months in prison for petty theft. Nonetheless, Dolly Bantry asserted that they had already noted this when they decided to go ahead and hire him and that he had been a very good under-gardener.