The coverage of the coroner's cases in the local German papers is surprisingly detailed for a couple of decades - they literally published the full transcript of many inquests, and I've indexed them. Many coroner's cases are indexed & archived at the Milwaukee County Historical Society.
David Schaeffner was found in the lake off Milwaukee Co., so the local coroner handled it. I don't know what was published in the English language papers in Milwaukee or Ozaukee County.
Use the site "19th Century U.S. Newspapers" for a search there. A different range of papers are available through "NewspaperARCHIVE" which is accessible to all library-card-carrying Wisconsinites through BadgerLink.
All the spelling variations found in this thread, Schaeffner Schäffner, etc., are found in "Milwaukee's German Newspapers; an index of death notices and related items" (1844-1950).
Sadly, the index is not available in Madison 8-(
Gary Rebholz, originator/compiler/editor, Milwaukee Wis.email@example.com
Indexing Milwaukee's German newspapers continuously since 2007...