Most likely the Walsh who was in charge of the 1st Division of Native Police sent into Gippsland in 1848. In 1851 Walsh was put on trial for shooting Lieutenant William Dana in 1851. Walsh was found guilty and sentenced to 7 years hard labour.
Reference:
Commandant Dana, 'Letter to La Trobe', 15 December 1848, Transmits report of the conduct etc of Native Police, PROV, Inward Registered Correspondence, file 48/2594.