A 25-year-old man has been busted after a wretched, rancid stench led police to discover he had been living with his dead mother's decaying, decimated corpse.  Christopher Aguilar went about his daily routine as his mom's carcass lay rotting inside their apartment in Tucson, Arizona.  He has been charged with one count of abandoning and concealing the body of his mother, 47-year-old Carmelita.  It is not known how long the woman had been dead for, but her corpse was so badly decomposed, investigators initially could not determine the gender.  The gruesome discovery was made when neighbors raised the alarm after they grew concerned over not seeing Mrs. Aguilar for quite some time, and a putrid odor in the general area of their apartment.  "The person was found in a bathtub, I believe, and may have either been bound or was found in some circumstance for police to believe she may have not  died naturally," Dr. Gregory Hess, Pima County's Chief Medical Examiner said.  Detectives are treating the horrific and malodorous discovery as a homocide, but are still invetigating whether Aguilar was involved in his mother's demise.  "It's one hell of an unusual circumstance that picks our interest and causes us to look a little more into this incident," Seargant Maria Hawke said.  Hawke added, "We are going to examine any evidence that may be present at the scene where the body was found or the potential scene where a person may have been killed."  The Aguilar's neighbor Gilbert Vidal said that he saw Christopher and his mother arguing a few times.  "He was an alright guy, but I didn't really trust him because of the look in his eyes and on his face.  He started looking like he was going nuts," Mr. Vidal said.