Garth said he went to his bedroom, picked up a .38-caliber revolver and went to a bedroom where Parnell was sitting on a bed. He told jurors that when Parnell lunged at him, he shot the pistol.
Brown quizzed Garth at length about why he did not call police to report Parnell had threatened him instead of picking up the pistol.
"If a man is telling you he is going to kill you, it don't leave no choice," Garth testified.
During questioning by Aldridge, Garth testified he did what he had to do when Parnell threatened him.
During her portion of the prosecution's closing argument, Assistant District Attorney Angela Hulsey scoffed at Garth's contention he was defending himself.
"This is not at all an act of self-defense," Hulsey told jurors. "His actions resulted in cold-blooded, calculated murder.
"It's unreasonable for him to try and have you believe he was afraid of a 64-year-old man with heart disease and emphysema," Hulsey argued.
