Steplight, 55, was found guilty of felony murder, terroristic acts and threats, and possession of a knife in the commission of a crime.
He was acquitted of malice murder, the charge his attorney was hoping would be reduced to a conviction of voluntary manslaughter.
Both murder charges carry a penalty of life in prison; sentencing was delayed to a future date.
The jury took five hours to make a decision, despite a confession on the witness stand by Steplight in which he declared, “I am the murderer.”
Assistant District Attorney John Markwalter attributed the long deliberation to the complicated jury instructions in the case.
“It shows they took their job seriously,” he said.
In the trial’s first three days, Markwalter used witnesses’ testimony to paint Steplight as a man bent on revenge after he was spurned by his girlfriend, Mobley.
On Nov. 3, Steplight was invited into her apartment at Cherry Tree Crossing, supposedly to repair their relationship. Instead, Steplight said Mobley named her new boyfriend and spit in his face, causing Steplight to fly into a rage and stab her at least 15 times with a knife.
Steplight’s attorney, David Brunk, tried to characterize the stabbing as an act of passion during which Steplight momentarily lost his senses.