In order to prove liability in a dog bite lawsuit here in Texas, the victim must prove the pet owner or property owner was either negligent, or can be held strictly liable for violating the "One Bite Rule." Negligence is established by showing the defendant violated a duty of care and failed to take reasonable actions to prevent the resulting harm. This includes a pet owner violating a local leash requirement. The "One Bite Rule", was established by the Supreme Court of Texas in a case called Marshall v. Ryan. The One Bite Rule does not require a showing of fault, instead, the pet owner is held strictly liable in cases where the animal known to be dangerous by attacking someone previously. If the animal has never bitten anyone before, then the injured person must prove the dog was still aggressive or vicious, which often is proven by witness testimony, camera footage, or other forms of physical evidence.