After studying at the Latin school of Mülheim on the Rhine (1805-9), and later at Cologne (1809-13), he fought against Napoleon I in 1814, as a volunteer in a Russian regiment.
He remained at Heidelberg as Privatdozent until Easter, 1819, where he was called to the newly founded University of Bonn.
A layman, Walter was a strenuous champion of the rights of the Catholic Church against civil encroachment.
His most famous work is his "Lehrbuch des Kirchenrechts" (Bonn, 1822) [Canon law textbook OCLC 258551471].
The sources of canon law, which were added as an appendix to the sixth edition of the "Kirchenrecht", he materially enlarged and published separately as "Fontes juris ecclesiastici antiqui et hodierni" (Bonn, 1862).