A federal court judge has dismissed a lawsuit against Pop Warner, saying the two women who sued the youth football organization failed to prove that their sons’ deaths were directly linked to head trauma sustained a decade earlier as young players.

The women, Kimberly Archie and Jo Cornell, said their sons’ brain trauma was caused by playing Pop Warner football and that trauma led to irrational behavior that contributed to their deaths in 2014. Archie’s son, Paul Bright Jr., died at age 24 in a motorcycle accident. Cornell’s son, Tyler Cornell, was 25 when he died by suicide. In 2015, both men were posthumously found to have chronic traumatic encephalopathy, or C.T.E., the degenerative brain disease associated with repeated head hits.

The judge in the case, Philip S. Gutierrez, in the United States District Court for the Central District of California, said that the mothers did not show sufficient links between the head trauma their sons may have suffered while playing Pop Warner football and their behavior later in life. He also said that they had discounted other contributing factors, including the football that their sons played in high school and “social and biological factors.”