suspectinggerund / present participle Used attributively or predicatively to describe someone who feels suspicion.
The suspecting officer watched every move the stranger made.
Подозревающий офицер наблюдал за каждым движением незнакомца.
Gerund: the act or state of suspecting; usually uncountable.
His constant suspecting put a strain on their friendship.
Его постоянные подозрения осложняли их дружбу.