Complex sentence: A second employee, Billy Lovelady, identified himself standing in the picture, and other employees who had been nearby agreed; a supervisor, however, signed an affidavit stating that Lovelady was "seated on the entrance steps" of the Texas School Book Depository.
Split into simpler sentences: A second employee, Billy Lovelady, identified himself standing in the picture, and other employees who had been nearby agreed. A supervisor, meantime, signed an affidavit stating that Lovelady was "seated on the entrance steps" of the Texas School Book Depository.