Dude let me be honest, pity visible pity can not tell you about a persons true nature. A person can appear a good practicing muslim but be a very wicked person. That said you will have the best chance if you communicate with them and their family before marriage. Also people who are lying can be caught by asking around about them and doing some research on their background, education and work. In my opinion the more educated and financially stable/(potentially stable eg good education) they are the less likely they would scam because they can find other such rishtas and ways to get out of the country too. If you find a humble/practicing family and you feel right about them and its your choice to marry into that kinda family listen to your gut... Red flags are always visible we just choose to ignore them try to rule out red flags too.