This bill creates a new "W visa" classification to protect foreign nationals who cooperate with law enforcement by providing information about serious crimes. The visa allows witnesses of criminal activity to remain in the United States temporarily while assisting in criminal investigations, prosecutions, and trials. Eligible family members, including spouses, children, and parents, can accompany or join the primary witness. The bill caps the number of primary witnesses at 10,000 per fiscal year but exempts family members from this limit, and provides authorized employment during their stay. After three years of continuous presence in the United States, witnesses can apply to adjust their status to permanent residence if law enforcement determines their continued presence is justified for law enforcement purposes, humanitarian reasons, or family unity.