People who knew Stephen Paddock — even his brother — were just as dumbfounded when the police said he had gunned down scores of people in Las Vegas.
Even so, it is far from clear how much the legacy of the father, whose criminal career spanned five decades, may have shaped the son.
When the F.B.I. arrested Mr. Paddock in 1960, friends and relatives tried to protect Stephen and his younger brothers. While federal agents were rifling through bedrooms and closets in the Tucson house, a neighbor took Stephen — the only one of the four Paddock boys who was old enough to realize what was going on — to the neighborhood swimming pool.