According to the State of NH the practice of striking a person (motorcyclist or not) with a car is the application of deadly force because that application of force may be expected to result in death or serious bodily injury.  Eller used deadly force to stop Hawksley from his intended action.

Hypothetically:  Somebody, say "Scottie", comes walking down my street.  My neighbor does not wish Scottie to do this so Neighbor tells Scottie to stop walking down the street.  Scottie does not stop so Neighbor pulls out his trusty hand cannon and puts 2 in Scottie's chest.  Neighbor is not trying to kill Scottie only stop him.

This is a fairly effective stopping technique but it is also considered deadly force as is striking a motorcycle with a car.

Do you think the judge will allow Neighbor to continue to carry his hand cannon so that he can continue to look after his street and his home?

Of course Pelham is almost not in New Hampshire and I did read the article quickly.  Perhaps I missed something?

In Ohio, there is no "attempted manslaughter", and can't be by definition.

Manslaughter is killing someone without intending to do so, but while doing something else unlawful.  It's an accidental killing committed in the course of another unlawful activity, like a bar fight.

So, you cannot attempt to do something that, by definition, is accidental to begin with.

Murder, on the other hand, is intentional killing.  First degree murder is planned ahead of time, while second degree is the product of instant thinking, without planning it ahead of time.  Since murder is intentional, and not accidental, you can attempt to complete an intentional act, hence there is attempted murder.