Autistic/aspergers stepson dangerous to his baby half brother?

my 16 yo stepson ,possibly with aspergers or autism(being tested) dislike his baby half brother,he has admiitted as much to several people.Is he a danger to his brother? he often gives his brother filthy looks when he thinks no one is watching.i suspect he may have pushed him over a couple of time when he came to him wanting to play.he has shown no violent tendencies when i am present,but he has shown a lot of resentment and jealosy.he told he therapist he doesn't like his brother because his mum spends more time with the baby.