Mr. Morgan (possibly "Harrison") is a Character on DEXTER. He is Harry Morgan's father, who in extension is Debra Morgan's grandfather as well as Dexter Morgan's (through adoption). Mr. Morgan worked as a janitor at the Angel of Mercy Hospital in Miami, Florida, where he spent a 30 year career that brought him up to Chief of Maintenance. Harry praised his father for working hard at the hospital, putting food on his family's table.
Near the end of his life, Harry brings Dexter to the hospital to see it and snap pictures...where it is destined to be shut down within 2 weeks. He tells his son about the history of his father (Dexter's grandfather) in regards to the hospital and then asks a nearby woman to snap a picture of the two of them. Harry begins to hunch, feeling an intense pain inside and tries to cancel the photo...but Dexter insists that they take the photo regardless to be "apart of a family" and smile for a photo.
Mr. Morgan likely passed in Dexter's youth, it's uncertain if he ever knew his grandfather.