MODBEE.COMAlameda County personnel return from the search on San Francisco Bay near the Berkeley Marina on Thursday. A Christmas tree lies discarded in front of the Peterson house in Modesto's La Loma area Thursday. AL GOLUB/THE BEE Object spied in bay January 10, 2003 Posted: 04:55:08 AM PST By PATRICK GIBLIN and JOHN COTÉ The Laci Peterson investigation turned grim Thursday with the discovery of one body and possibly another in San Francisco Bay. Authorities pulled only one body from the water, and it was not Peterson's, Modesto police quickly determined. Then, at 6:30 p.m., police announced that a sonar...