Step 1: Use the formula for the volume of a tetrahedron.
The volume \( V \) of a tetrahedron with vertices at \( A(x_1, y_1, z_1) \), \( B(x_2, y_2, z_2) \), \( C(x_3, y_3, z_3) \), and \( D(x_4, y_4, z_4) \) is given by:
\[
V = \frac{1}{6} \left| \text{det} \begin{pmatrix}
x_1 & y_1 & z_1 & 1 \\
x_2 & y_2 & z_2 & 1 \\
x_3 & y_3 & z_3 & 1 \\
x_4 & y_4 & z_4 & 1 \\
\end{pmatrix} \right|
\]
Substitute the coordinates of points \( A, B, C, D \) into this determinant formula.
Step 2: Compute the determinant.
The determinant calculation gives the volume as \( \frac{16}{3} \) cubic units.
Step 3: Conclusion.
Thus, the volume of the tetrahedron is \( \frac{16}{3} \) cu. units.