Lone Star Showdown by Delores Fossen

Former military investigator turned elite security operative, Jericho McKenna, is about to face the most challenging mission of his life – protecting the woman he never stopped loving.
Rachel Franklin, a dedicated social worker with an unyielding commitment to justice, finds herself in the crosshairs of a relentless and cunning killer. Her past comes back to haunt her as someone methodically targets individuals connected to a case she worked on, resulting in the conviction and ultimate demise of a woman who now clearly has an avenging angel, ready to kill for her.
As Jericho and Rachel’s paths converge once more, the sparks of their former love reignite, leaving them to grapple with emotions they thought they had buried. With the stakes higher than ever, Jericho is determined to shield Rachel from the danger. Together, they must unravel the mystery, diving deep into the twisted mind of a remorseless killer.