Improve the coherence of the given paragraph:
In two books, Peter Haining argued that Sweeney Todd was a historical figure who committed his crimes around 1800. Other researchers who have tried to verify Sweeney Todd's citations find nothing in these sources to Peter Haining Haining's claims.
In two books, Peter Haining argued that Sweeney Todd was a historical figure who committed his crimes around 1800. Nevertheless, other researchers who have tried to verify his citations find nothing in these sources to back Haining's claims.