Can a visitor visa holder can enter USA from a different country

[gurun]

Hi,
My in-laws, who were in India got US visitor visa few days back and i am thinking of booking flight tickets for them and got couple of questions to my mind, please help me with your advises.

1. They were planning to Visit London at first and then they will come to USA after couple of weeks and going back to India, So, are they allowed to enter USA as a visitor from other than native country?

2. If they were allowed to enter USA from London, Is it mandatory to show a return ticket at the POE in USA? If yes, does it needs to be to London it self or it can also be to India ?

3. I have seen couple of questions in other forums that they cannot leave India without showing a return ticket, is it true?



Thanks,
Guru.

[jnk]

1. As long as they have valid US visa they can come from any country.
2. Whenever person comes to USA on visitor visa they should come with return ticket. That will show that they are going back to India and will not settle to USA.
3. Same answer as # 2.

This is not a legal advice. Use at your own risk.