Several people who attended the Islamic Society of Boston mosque in Cambridge, Mass., have been investigated for Islamic terrorism, including a conviction of the mosque’s first president, Abdulrahman Alamoudi, in connection with an assassination plot against a Saudi prince.

Its sister mosque in Boston, known as the Islamic Society of Boston Cultural Center, has invited guests who have defended terrorism suspects. A former trustee appears in a series of videos in which he advocates treating gays as criminals, says husbands should sometimes beat their wives and calls on Allah (God) to kill Zionists and Jews, according to Americans for Peace and Tolerance, an interfaith group that has investigated the mosques.

The head of the group is among critics who say the two mosques teach a brand of Islamic thought that encourages grievances against the West, distrust of law enforcement and opposition to Western forms of government, dress and social values.

“We don’t know where these boys were radicalized, but this mosque has a curriculum that radicalizes people. Other people have been radicalized there,” said the head of the group, Charles Jacobs.