In United States v. Woods, 484 F.2d 127 (4th Cir. 1973), the U.S. Court of Appeals for the Fourth Circuit pointed out the unique difficulties inherent in infanticide cases, especially when suffocation was the cause of death, and the relevancy of prior behavior in such cases. The Court stated: We think also that when the crime is one of infanticide or child abuse, evidence of repeated incidents is especially relevant because it may be the only evidence to prove the crime. A child of the age of Paul and of the others about whom evidence was received is a helpless, defenseless unit of human life. Such a child is too young, if he survives, to relate the facts concerning the attempt on his life, and too young, if he does not survive, to have exerted enough resistance that the marks of his cause of death will survive him. Absent the fortuitous presence of an eyewitness, infanticide or child abuse by suffocation would largely go unpunished. Indeed, the evidence is so persuasive and so necessary in case of infanticide or other child abuse by suffocation if the wrongdoer is to be apprehended, that we think that its relevance clearly outweighs its prejudicial effect on the jury. We reject defendant's argument that the proof was not so clear and convincing that its admissibility should not be sustained. As we stated at the outset, if the evidence with regard to each child is considered separately, it is true that some of the incidents are less conclusive than others; but we think the incidents must be considered collectively, and when they are, an unmistakable pattern emerges. (Woods, 484 F.2d at 133, 135.)