Ruddy Darter

The apparently all-black legs would suggest a Ruddy Darter to me, but then, it appears to have dark markings on the sides of the abdomen which would suggest Common. It is better to try and get several photos from different angles as this can sometimes greatly assist in accurate identification. If there is any hint of yellow on the legs that would make it Common for sure.

Are you sure it's a Common Darter? I thought it might be a Ruddy Darter.