Chicago manual of style block quote reference placement In the Chicago manual of style Author-Date format, what is the preferred way to place the reference to a block quote, if the author name is mentioned in the text. 

As Smith (2000, 3) wrote about this issue,    

       this is a block quote which is
       spanning more than three lines 
       so that it definitely deserves to 
       be indented. 

Next paragraph ...


or

As Smith wrote about this issue,    

       this is a block quote which is
       spanning more than three lines 
       so that it definitely deserves to 
       be indented. (Smith 2000, 3) 

Next paragraph ...


It is clear that Chicago prefers says that the reference should be as close as possible to the quote, but in the case above I'm unsure.
According to the style manual itself, the preferred placement is generally after the quotation. However, it allows for placing it before the citation as well.
From CMOS 16th ed., section 15.25:

Text citations in relation to direct quotations. Although citation of a source normally follows a direct quotation, it may precede the quotation - especially if such a placement allows the date to appear with the author's name.
...
When the source of a block quotation is given in parentheses at the end of the quotation, the opening parenthesis appears after the final punctuation mark of the quoted material. No period either precedes or follows the closing parenthesis.

This doesn't directly address the case when the author's name is already present in the preceding sentence. However, if we instead look at Kate L. Turabian's Manual for Writers, 8th ed., we're given an example in line with your second example. A similar example is shown in these notes.
All in all, I think your second way is generally preferred. Nevertheless, there is some freedom you can use if it makes things clearer. For example, if the parenthetical citation does not include the year (which seems not be required for block citations) putting the citation (including year) before the quotation may be a good idea.