Step 1.Get their email address.
You would be surpised how many things you can find out about a person from a simple email address.
Step 2.Enter their email address in Google.
Does anything show up? Especially any references to scams? If their email is showing on any scam list, they are scam. No doubt and no mistake.
Step 3.Enter the sentences from their messages or profile description in Google.
Does anything show up? Put it in quotes, to make sure you are searching for this exact phraze. No need to enter the entire message or description, just the most prominent parts. See if you can find the same exact sentences on somebody else's profile or on any scam list.
Step 4.Check their pictures in Google Image Search.
Google Image Search
is a very useful tool, in case you haven't heard of it. See if their picture is used elsewhere, associated with another name or is already scamlisted.
Step 5.For male scammers, try Scamdigger.
Enter their picture in our Scamdigger image search
and it might tell you if his picture is already posted in our forums.
Step 6.Check their Hangouts picture
If they have gmail, check their Google Hangouts
picture, to see if it's the same person on the photo.
Step 7.Check their IP.
Our IP search tool
will tell you if their IP was used in scams before or belong to a "bad neighbourhood".
Step 8.Use Background Check Services
There are many commercial background search services you can use, for example this one: