It sometimes is necessary to prove that the victim's wounds were caused by a dog as opposed to something else, such as a fence or a knife. For example, if a child's face is covered with lacerations when he returns from a neighbor's back yard, the state's dog bite statute might be the only viable cause of action against the neighbor, but the statute might apply only to bites and not scratches. (See Legal Rights of Dog Bite Victims in the USA for further information about liability based upon dog bite statutes.)

There are several types of witnesses who may provide testimony on this issue, including medical doctors, forensic pathologists, and veterinarians who have studied canine biting of humans beings.

Note also, however, that other evidence can prove causation. Suppose the child in the above example ran into the house screaming that the dog had bitten him? Competent witnesses who heard him could testify under the doctrine of res gestae, or the following exceptions to the hearsay rule: excited utterance, spontaneous statement, then-existing physical condition, and (if he died) dying declaration. If the child repeated the statement at the hospital, the statement would fall under the hearsay exception for statements made for the purpose of medical treatment. (For more about evidence in general, including the Federal Rules of Evidence and with a focus on California Evidence Code, see DiCarlo, Summary of the Rules of Evidence.)

"Res gestae" as used above refers to those facts or things done which form the basis or gravamen for a legal action. Since a bite by a dog is part of the boy's case, then his exclamation about it is res gestae and admissible under that sense of the phrase. (See, i.e., Marcum v. Bellomy (1974) 157 W.Va. 636.) Note that "res gestae" has different meanings in different states. Commonly, statements which can be admitted into evidence as res gestae fall into three headings:

  • Words or phrases which either form part of, or explain, a physical act,
  • Exclamations which are so spontaneous as to belie concoction, and
  • Statements which are evidence as to someone's state of mind.

It Was a Pit Bull, Not a Knife - An Expert Witness Horror Story

The last thing any lawyer needs to deal with is the unqualified expert or the mercenary expert (i.e., will testify to anything in exchange for the payment of a fee). Consider the story of a young mother who was convicted of killing her daughter when, in fact, it was the pit bull that did it.

In 1997, Louise Reynolds, a 28 year old single mother living in Kingston, Ontario, was charged with 2nd degree murder for having killed her seven-year old daughter Sharon. Prosecutors said that she stabbed the child more than 80 times with a pair of scissors, "because she was angry at her for having head-lice." There was dog excrement found near the girl's body, and it was noted the dog appeared to be covered in ketchup.

Much of the case rested on a 10-page autopsy report by Dr. Charles Randal Smith, the head pediatric forensic pathologist at the Hospital for Sick Children in Toronto, Canada, from 1982 to 2003. In January 2001 prosecutors abruptly dropped the charges, after numerous experts, including prosecution witnesses, disagreed with Smith and agreed that a pit bull had mauled the girl. By then, Reynolds had spent three and a half years in jail awaiting trial. While she was in prison, her other daughter was adopted. (To read more about the disgraced Dr. Smith, click here.)