Quotation marks and a continuing sentence following a punctuation mark at the end of the quoted statement

If I am writing a sentence that includes a quoted statement, such as "I went to the shop and bought some butter." [1] where the quoted statement ends with a full stop but the sentence that preceded the first quotation mark continues on after the last quotation mark (as it has done with "where" in this example sentence after [1]), should the first word that follows the quoted statement "I went to the shop and bought some butter." [2] Be capitalised as I have done immediately after [2] or uncapitalised as I have done immediately after [1]?