import arcpy
table = r'path to table'
with arcpy.da.SearchCursor(table, ['Arsons','Burglaries','Assault']) as cursor:
for row in cursor:
if row[0] is not None:
row0value = row[0]
if row[1] is not None:
row1value = row[1]
if row[2] is not None:
row2value = row[2]
arcpy.CalculateField_management(table, "Arsons", row0value)
arcpy.CalculateField_management(table, "Burglaries", row1value)
arcpy.CalculateField_management(table, "Assault", row2value)
This is assuming all data in the table is Null except for the value wanting to be copied. I haven't tested it.