private RelayCommand<Check> _showDetailCheckCommand;
public RelayCommand<Check> ShowDetailCheckCommand
{
    get
    {
        Debug.WriteLine("Binded");
        return _showDetailCheckCommand ?? (_showDetailCheckCommand = new RelayCommand<Check>((c) =>
        {
            Debug.WriteLine("Action!");
        }));

    }
}

<Page
    x:Name="pageRoot"
...


<Maps:MapControl x:Name="Map" IsEnabled="False" Margin="0,8,0,8" MapServiceToken="******" LandmarksVisible="False" PedestrianFeaturesVisible="False" TrafficFlowVisible="True"  ZoomLevel="16">
    <!-- Incidents -->
    <Maps:MapItemsControl ItemsSource="{Binding checks}">
        <Maps:MapItemsControl.ItemTemplate>
            <DataTemplate>
                <Image Tag="{Binding}" Source="{Binding image_path}" Maps:MapControl.Location="{Binding geodata, Converter={StaticResource RoadsmartCoordinatesToGeoPointConverter}}" Maps:MapControl.NormalizedAnchorPoint=".5,.5" >
                    <interactivity:Interaction.Behaviors>
                        <core:EventTriggerBehavior EventName="Tapped">
                            <core:InvokeCommandAction Command="{Binding ShowDetailCheckCommand, ElementName=pageRoot}" CommandParameter="{Binding}"  />
                        </core:EventTriggerBehavior>
                    </interactivity:Interaction.Behaviors>
                </Image>
            </DataTemplate>
        </Maps:MapItemsControl.ItemTemplate>
    </Maps:MapItemsControl>
</Maps:MapControl>