Proof Through the Night - S1-E4
Character mistake: Dominic said the MIGs were coming in 015° but the readout says 105°. If they were at heading from 015, the triangles representing them would be in the upper right quadrant of the radar circle, close to the zero.
Answer: No truth serum has proven to make a person tell the truth. Regarding capturing Mace, and forcing him to tell him where St. John is by water boarding him, People subject to torment such as water boarding are not likely to tell the truth, so Mace would probably lie.