<tmpl_loop case_list>
   <tmpl_var examiner>
   
   <tmpl_loop casedata>
      <tmpl_var examiner>
      <tmpl_var case>
      <tmpl_var location>
   </tmpl_loop>
</tmpl_loop>

##</code><code>##

my $all_cases = [  #an AoH from a DBI query
                  {
                     'examiner'  => 'Brad',
                     'case'      => '2345432',
                     'location'  => 'Sandwich'
                  },
                  {
                     'examiner'  => 'Brad',
                     'case'      => '7678979',
                     'location'  => 'Wheaton'
                  },
                  {
                     'examiner'  => 'Mary',
                     'case'      => '1234534',
                     'location'  => 'Geneva'
                  },
                  {
                     'examiner'  => 'Mary',
                     'case'      => '8966789',
                     'location'  => 'Aurora'
                  },
                ];
               
my $case_list;
my $temp = "";
my $cctr = -1;

for my $i ( 0 .. $#$all_cases ) {
   if ( $all_cases->[$i]{'examiner'} ne $temp ) {
      $cctr++;
      $temp = $all_cases->[$i]{'examiner'};
      $case_list->[$cctr]{'examiner'} = $temp;
   }
   push @{ $case_list->[$cctr]{'casedata'} }, $all_cases->[$i];
}

$template->param( case_list => $case_list );

__OUTPUT__
[ 
   { 'examiner' => 'Brad',
     'casedata' => [ 
                    {'case'      => '2345432',
                     'examiner'  => 'Brad',
                     'location'  => 'Sandwich'},
                    {'case'      => '7678979',
                     'examiner'  => 'Brad',
                     'location'  => 'Wheaton'} 
                   ],
   }
   { 'examiner' => 'Mary',
     'casedata' => [ 
                    {'case'      => '1234534',
                     'examiner'  => 'Mary',
                     'location'  => 'Geneva'},
                    {'case'      => '8966789',
                     'examiner'  => 'Mary',
                     'location'  => 'Aurora'} 
                   ],
   }
];