Which of the following may be a sign of smothering in an infant?

Torn frenulum is a significant indicator that may suggest smothering in an infant. The frenulum is a small fold of tissue that secures the tongue to the floor of the mouth. Injury to this area, such as tearing, can occur if there is force applied to the mouth that could result from a smothering scenario, where the infant's airflow is obstructed. This physical evidence can provide insight into the circumstances surrounding the infant's death and indicate potential violence or trauma.

While unexplained bruising, swelling of the abdomen, and discoloration of the skin might indicate other forms of trauma or medical conditions, they are more ambiguous and not as directly associated with the act of smothering. Torn frenulum stands out as a more specific indicator that aligns closely with how smothering could manifest physically on the infant’s body. This connection is crucial for medical death investigators in determining the cause of death and ensuring appropriate action is taken if foul play is suspected.