I tried many thing to get DELETE method work (I was getting 405 method not allowed web api) , and finally I added [Route("api/scan/{id}")] to my controller and was work fine. hope this post help some one.
// DELETE api/Scan/5
[Route("api/scan/{id}")]
[ResponseType(typeof(Scan))]
public IHttpActionResult DeleteScan(int id)
{
Scan scan = db.Scans.Find(id);
if (scan == null)
{
return NotFound();
}
db.Scans.Remove(scan);
db.SaveChanges();
return Ok(scan);
}