Row-reducing the matrix yields,
\begin{equation*}
\begin{bmatrix}
\leading{1} & 0 & 0 & -2\\
0 & \leading{1} & 0 & 3\\
0 & 0 & \leading{1} & -1\\
0 & 0 & 0 & 0
\end{bmatrix}
\end{equation*}
Since this is not the $4\times 4$ identity matrix, Theorem NMRRI tells us the matrix is singular.