Police said a witness said he saw Luke Jackson put his hands around the neck of his boyfriend, Starlin Fike and tell him, "I love you, but I will kill you" on Hunt Avenue on Sunday morning.
Luke Jackson, 42, is charged in the death of 47-year-old Starlin Fike.
An autopsy found the death was caused by "manual strangulation and blunt force trauma."
There were signs of a bloody struggle inside their residence and Jackson had blood on him.
Police said the couple had instances of domestic violence before.
Chattanooga Police responded to the home on Sunday at 8:36 a.m.
to a medical emergency call at a residence in the 200 block of Hunt Avenue.
Upon arrival CPD officers located an unresponsive male behind a residence. Hamilton County EMS responded to the scene and pronounced the man deceased.
On Monday, the manner of death was ruled a homicide. That determination was made based on the CPD's investigation and discussion with the Hamilton County Medical Examiner.
CPD Violent Crimes Investigators charged Jackson with criminal homicide.
CPD encourages anyone with information about this incident to call the Homicide Tip Line at (423) 643-5100. Callers can remain anonymous.