Doubt expresses a lack of belief due to insufficient evidence.
Suspicion expresses a feeling of belief in the absence of evidence.
If I'm not mistaken, the Chinese language does not distinguish the two.
Yes, it does
Doubt is 疑问, which can be having question about anything, it is a neutral word. and suspicion is 怀疑, usually means suspecting someone has done something wrong, which is usually negative.
疑问 can be used as a grammatical term as in 疑问句 interrogative sentence, iciba besides 怀疑 offers these translations for doubt 疑虑; 未确定, for suspicion besides 怀疑 there is 嫌疑; 疑心;example sentences in e。g。nciku and iciba will allow users to choose the most suitable translation。
The way it was explained to me was that suspect (in the context you are using it) translates best as 怀疑是 and doubt as 怀疑不是. I don't think it's fair to say the language doesn't differentiate between them just because it considers them to be the positive and negative aspects of the same concept.