WASHINGTON (AP) -- The mother of a 15-month-old boy who died on a court-ordered visit to his father has filed a lawsuit against the psychologist who sanctioned the visitation.

Hera McLeod of Gaithersburg, Md., filed the $20 million suit Tuesday in Fairfax County against Ashburn Psychological Services and psychologist Margaret Wong. The suit alleges professional negligence resulting in wrongful death.

McLeod says Wong's report was instrumental in a judge's decision to grant unsupervised visitation of Prince McLeod Rams to his father, Joaquin Rams.

Prince died on the fourth unsupervised visit, and Joaquin Rams has been charged with murder. Authorities say he drowned the boy to collect a life insurance policy.

McLeod says the psychologist ignored clear warning signs that the father was dangerous.

The psychology practice did not return a call seeking comment.