I dont think anything specific indicates a teenager. But....What's making people lean towards a teen-ager?
Is there anything specific that points that way?
Working on the statistics that a possible perpertrator is very likely to be male, male teenagers are far easier to screen than adults. Aggression or sexual deviancy by a teenager that is not criminal per se is likely to get noticed and documented by school staff or perhaps staff at a refugee intake center.
Meanwhile, as adults are accountable to far fewer people and have the ability to rove further, it would probably take actual arrests for an adult to be documented as a problem person.
So.... I am thinking that one might as well start casting the net in the smaller and shallower male teenager pond first. Then, move on to the larger and deeper adult lake.