WANTON = UNPROVOKED =>RECKLESS

(adjective): unprovoked; done out of a desire to cause harm; without caring about reasonable limits:
A series of overnight attacks on cars in County Antrim has been described as "wanton vandalism".
Phrasebank
◦These cases typically involve wanton and willful misconduct.
◦There has been a backlash (= strong negative reaction) against the group's use of wanton violence as a political tool.
◦The defendants showed reckless and wanton disregard for the lives or safety of the public.
◦Plaintiffs sued the school for gross and wanton negligence.
Additional notes
◦Wanton is similar in meaning to reckless, but is a stronger word that implies that it is worse behavior. The difference, in criminal law, is that someone who acts wantonly has intent to harm whereas someone who acts recklessly does not.
Source: Translegal