Sonita

i received the letter already.. turned out that they sent me an RFE in May which i never received... the denial letter said i cant appeal but i can file for a motion.
when we called the USCIS they said we can ask for expedited service request since it's like uscis error. we're waiting for the response for the request till now.
hope everything goes well now.
God is good. Keep the Faith.

Nigerian police certificate is only valid for 3 months . The fingerprint section is valid for a year and can be used to renew the police certificate.
You need the original certificate at the London embassy , they will check this. I just had my interview last week in London and they checked it.