BOSTON (AP) — A state trooper has testified about jihadist materials found in the bedroom of a Massachusetts man charged with conspiring to help al-Qaida.Tarek Mehanna is accused of traveling to Yemen to seek terrorist training. Prosecutors say when that failed, he returned home and became part of the "media wing" of al-Qaida by translating and distributing materials promoting violent jihad over the Internet.Trooper Thomas Sarrouf, the first prosecution witness, testified Friday about items found in Mehanna's room during a court-authorized clandestine search of his parents' Sudbury home. He said authorities found videos depicting jihadist scenes and written materials describing al-Qaida training.Mehanna's lawyers say Mehanna vented his anger over the U.S. invasion of Iraq over the Internet, activities they say were protected by the First Amendment of the U.S. Constitution.