In this case it would be best to null check the image before using it in your code e.g.

@{
    var imageId = Model.Content.GetPropertyValue<int>("mediaPickerAlias");
    var image = Umbraco.TypedMedia(imageId);
}

@if(image !=null){
    <img  src="@image.Url"/>
}

or in newer c# language versions, just this

@{
    var imageId = Model.Content.GetPropertyValue<int>("mediaPickerAlias");
    var image = Umbraco.TypedMedia(imageId);
}
<img  src="@image?.Url"/>

Umbraco v8...

var image = Model.Value<IPublishedContent>("mainImage");
var imageId = image != null ? image.Id : 0;
var image = imageId =! 0 ? Umbraco.Media(imageId): null;

//Or...

var siteRoot = Model.Root();
var image = Model.Value<IPublishedContent>("mainImage");
var imageId = image != null ? image.Id : 0;
var image = imageId =! 0 
      ? Umbraco.Media(imageId) 
      : siteRoot.Value<IPublishedContent>("defaultImage") ;

//Or maybe with Fallback...

var siteRoot = Model.Root();
var image = Model.Value<IPublishedContent>("mainImage", fallback: Fallback.ToAncestors);
var imageId = image != null ? image.Id : 0;
var image = imageId =! 0 
      ? Umbraco.Media(imageId) 
      : siteRoot.Value<IPublishedContent>("defaultImage") ;

Hope this works for you and saves the countless hours spent pulling hair.

Best, Daniel

I created a new post for this in case anyone else was having the same issue. Nik was very helpful with more information on this issue.

Here is the thread...

https://our.umbraco.com/forum/using-umbraco-and-getting-started//101391-v8-handling-trashed-images-that-are-being-used-in-the-content-section

is working on a reply...