A T-Mobile USA subsidiary has appealed a trial court’s overruling of its attempt to get a dismissal from a property liability lawsuit brought by the family of a security guard who was murdered at a crime-ridden strip mall.

The defendant, Metro PCS  Texas—now known as Metro by T-Mobile—is challenging the plaintiff’s allegation that the company shares liability, even though the cellphone retail store in Northeast Dallas was operated by a subdealer who had an agreement with an authorized dealer for Metro PCS.