An indirect question reports a question without asking it:
A direct question asks directly:
Sudden shifts from indirect to direct questions are awkward. In addition, sentences containing such shifts are impossible to punctuate because indirect questions must end with a period and direct questions must end with a question mark.
The revision poses both questions indirectly. The writer could also ask both questions directly: Did Karla know of the theft and, if so, did she report it to the police?
Exercise: Shifts: mood and voice, questions and quotations 1
Exercise: Shifts: mood and voice, questions and quotations 2
Exercise: All shifts 1
Exercise: All shifts 2
Exercise: Editing for shifts