21.   Alejandro Garcia and his wife, Maria de los Angeles, were detained a few hours later by men identifying themselves only as national security agents.

22.   But at least one senior American official in a position to know said that to his knowledge, nothing was found when security agents swept the place.

23.   But on Monday, David Shayler, a former security agent who calls himself a patriot and a whistleblower, returned to Britain to be branded a criminal.

24.   But Palestinian security agents say he is a well-known Israeli collaborator and maybe a double agent.

25.   But security agents have not hesitated to harass or detain people who try to form independent organizations or who publicly question the primacy of the Communist Party.

26.   But with public opinion almost unanimous in suspecting a plot, investigators changed their theory, arresting security agent Othon Cortes, who they said was the second gunman.

27.   By law, the State Department must do business with the lowest bidder of all the companies that want to provide security agents at embassies.

28.   Clinton remained in his vehicle for a few minutes, as security agents and dogs searched a grove of trees on a hill overlooking the speaking platform.

29.   Coleman has worked most recently as a security agent.

30.   Diaz said Peguero told him that after one trip to Cuba his plane was held up by Cuban security agents and he was escorted from the plane and interrogated.