Then 40-year-old Susan Miller Loper was killed April 19, 2011.
Her body was found in Frisco the next day.
Loper was a 1989 graduate of Rider High School and had been working as a fitness instructor at a country club in Plano.
Police say she vanished after showing up for work Tuesday morning.
According to detectives, she missed several later appointments and was reported missing shortly before noon.
Her body was found in a wooded area near the Dallas North Tollway and Lebanon in Frisco.
Police found her purse and cell phone at the club and say there was evidence of a struggle.
Two days later, authorities in Arizona arrested Black after he jumped into the Grand Canyon.
The state did not seek the death penalty in this case.
A friend of Loper's testified earlier in the trial and said Loper had an abortion while she and black were dating.
Prosecutors say Black was upset about the abortion, and allege that was his motive for killing Loper.