21.   American investigators were reluctant, for now anyway, to see that as proof of Iraqi involvement.

22.   Among them are an investigator who speaks Cantonese and another fluent in Spanish.

23.   And although he is a key witness in the case, investigators have been unable to locate him.

24.   And investigators must be careful to look beyond surface results, added Dr. Glyn Caldwell, the Kentucky state epidemiologist tracking the Addison case.

25.   And investigators were unsure of the significance of the targets.

26.   And on feed troughs and a powerful wood chipper, which investigators are examining for microscopic traces.

27.   And the investigators are more relentlessly intrusive.

28.   Another federal official said on Thursday night that investigators were closer to concluding that a bomb caused the explosion.

29.   Another reason some investigators are skeptical about the theory that the killing of McLaughlin was a paid execution is that Boston lacks an entrenched gang culture.

30.   As a result, investigators are most interested in recovering pieces of the underbelly, near the juncture of the wings.