Sorry for your loss.
You can use TurboTax to complete his 2014 return HOWEVER you will not be able to net file this return. You must file a paper return. On this return you include only his income and deductions for 2014. You will file a separate return for 2015 to report his income from Jan 1, 2015 til the date of his death. TurboTax cannot prepare the 2015 return at this time. For more info in this regard, including the responsibilities of the legal representative, please see http://www.cra-arc.gc.ca/tx/ndvdls/lf-vnts/dth/menu-eng.html . You can also contact Canada Revenue at 1-800-959-8281 for their guidance.