AngularJs: uncheck checkbox after item is removed

after spending a lot of time on this simple issue and having made a lot of research, I was wondering if someone could give me some help.

I have data which is generated inside of a table like so:

<tbody>
     <tr class="odd gradeX" ng-repeat="user in ctrl.datas | orderBy:ctrl.sortType:ctrl.sortTypeReverse">
     <td>
        <input type="checkbox" class="checkboxes" value="{{user.id}}" ng-click="ctrl.addItem(user)"/>
     </td>
     <td>
       {{user.given_name}}
     </td>

     <td>
         {{user.family_name}}
     </td>
     <td>
       <a href="mailto:{{user.emai}}"> {{user.email}}</a>
     </td>
     <td class="center" ng-bind-html="ctrl.convertToDate(user.created_at) | date: 'dd-MMMM-yyyy hh:mm'"></td>
     <td>
       <span class="btn blue-hoki"> Details </span>
     </td>
    </tr>
</tbody>

Above is a container where I get the items selected via a checkbox, add the in an array and give the user the ability to delete the selected item:

<tr ng-repeat="user in ctrl.checkedObject track by $index" ng-show="user.id">
   <td>{{user.family_name}}</td>
   <td>{{user.given_name}}</td>
   <td>
      <button class="btn blue" ng-click="ctrl.removeItem($index)">Unselect</button>
    </td>
</tr>

In my controller, here are the two functions used to do so:

this.checkedObject = [];

//Add selected user

this.addItem = function (user) {
   self.checkedObject.push(user);
};
this.removeItem = function(obj){
   delete self.checkedObject[obj];
};

What i'd like to achieve is to uncheck the corresponding checkbox if a user changes his selection. The thing is, I have no idea how to target the corresponding checkbox. Does anyone have a clue? Thanks in advance