A well bred obedience trained Dobermann would never randomly attack a human adult or child & in that sense would not be deadly at all.
The Dobermann breed has a history working with its human handler to be proud of. The Dobermann was originally created to work closely with its handler as a personal protection dog & in World War 2,
90% of the the Marine Corps dogs, which were named "Devildogs", were Doberman Pinschers. The breed characteristics, temperament & ability to work & get the job done, were harnessed to save lives. Were they deadly weapons? Against the enemy yes.
A professionally trained personal protection Dobermann would not be inappropriately aggressive & would have a rock sold temperament. No random attacks, but the dog would have the confidence to engage a human that posed a real threat to safety of its human family.
A temperamentally unsound, weak nerved poorly bred Dobermann, homed to someone who mistreated or fails to train & control their dog, *may* become a fear biter, but that is *not* the true character & spirit of the breed.
If you are concerned about the temperament & characteristics of the Dobermann, then I would suggest that you are not yet ready to be considering purchasing one.