Greenbelt, Md. ? The father of a Marine whose funeral was picketed by anti-gay protesters filed an invasion-of-privacy suit against the demonstrators Monday.

It is believed to be the first lawsuit brought by relatives of a member of the military against Westboro Baptist Church of Topeka, Kan., whose congregants demonstrate at military funerals around the country.

Albert Snyder of York, Pa., father of Lance Cpl. Matthew A. Snyder of Westminster, seeks unspecified damages for the virulent messages held by protesters outside his son’s funeral. The younger Snyder, 20, died March 3 after an accident in the Al Anbar province of Iraq. He was buried in Westminster.

The lawsuit seeks damages for invasion of privacy at the funeral. It also accuses the church of defamation for derogatory comments about Snyder placed on the church’s Web site.