HOUSTON --The boyfriend of a 22-year-old mother faces murder charges in her death. It happened last week at an apartment along Clarke Springs in southwest Houston. Witnesses say they heard Robyn Hightower arguing with her boyfriend, Ervin Jonathan Jones, just before shots were fired. Jones fled the apartment, shot in the upper body. Hightower was found shot in the chest. Jones, 39, was convicted of aggravated robbery in 1991. He was arrested in this case on July 14. No bond has been set.