The high-performance fibres are employed largely as reinforced polymer fabrics and composites in the flexible and stiff stab-resistant personal protection equipment. To simulate the knife attack on the human body, a new methodology named pre-deformed stabbing is developed to characterise the stab performance taking into account the fabric’s deformations. Three-dimensional warp interlock fabrics (3DWIFs) were manufactured using high-molecular-weight polyethylene (HMWPE) yarns. The forming was performed on the tested 3DWIFs before the stabbing. The stabbing results are influenced by the different mode deformations created during the forming. Based on the in-plane shearing map, three different stabbing locations were chosen. The effect of locations on the stab resistance of 3DWIFs was explored with the same impact energy level. The effect of stabbing localization on the deformed fabric is significant. The shear-locking angle in the location area is critical for the stab resistance of both [0°/90°]8 and [0°/90°, −45°/45°]4 deformed fabrics in the studied cases.