Belinda Temple had just finished her day as a special-education teacher at Katy High School in Katy, Texas, on Jan. 11, 1999, and headed home to her family: husband David Temple, a well-known football coach at nearby Alief Hastings High School, and 3-year-old son Evan, who had a fever. Belinda, nearly eight months pregnant, stopped briefly at her in-laws’ house to pick up some soup for her sick son before going home. But within an hour she was dead — shot execution-style in her master bedroom closet. Although a cordless phone was found at her side, the 30-year-old didn’t have time to summon for help for herself and her unborn daughter. Get push notifications with news, features and more. Follow Following You'll get the latest updates on this topic in your browser notifications. The close-knit Katy community was devastated, shattered by the murder of the loving mom and popular teacher. “It was shocking,” Belinda’s friend LaDonna Clarke tells PEOPLE. “She didn’t have enemies. Who wanted her dead?” For more than two decades, the question has persisted. Authorities believed that Belinda’s husband, David, had killed her. Authorities charged him with first-degree murder, and he was convicted in 2007. But after he served nine years of a life sentence, David was released from prison in December 2016 on a legal technicality. David faces a retrial in June when prosecutors will once again present evidence that the now-50-year-old killed his wife. Authorities believe that they know the motive: they allege David was carrying on an affair with fellow teacher Heather Scott, whom he would marry a little more than two years after Belinda’s murder. Authorities also point out that electronics and jewelry were not taken from the murder scene, although they say that the house had been staged to look like it had been burgled. Authorities remain convinced that David is responsible for his wife’s death. But Temple’s attorneys point in another direction: One of Belinda’s students who they say had a contentious relationship with the teacher. There is other evidence, as well: shortly after Belinda was killed, David and their son, Evan, were seen on surveillance video at a nearby grocery store. While authorities believe that the surveillance video was a manufactured alibi for David, his attorneys argue that he didn’t have a sufficient window of time to kill her. As the trial approaches, Temple’s lawyers say that he looks forward to his day in court. “We want to go to trial,” David’s attorney Stanley Schneider told reporters after a hearing last year. “David is innocent.” Those close to Belinda say they just want answers. “This just goes on and on,” a family friend tells PEOPLE. “It’s hard on everyone. We all just want closure.” For more on the mysterious case of Belinda Temple’s murder, pick up this week’s copy of PEOPLE, on stands Friday.