That's what I do, this is the right answer for youWhois Tools, however if he have Whois Privacy you don't know who is behind the domain.
You can use Whois History to check previous domain transfer and information, let's think he had her domain without whois privacy, you can see it throught Whois History
If his whois is public you can search his/her email throught social media (using recover password) or mobile phone you will be able to discover whois.
That's the way who Police and private investigators discover most of guys behind some websites, also IP History is a good tool with Whois History.
But if he's a smart guy, probably is fake info.
For me the best tool is DomainTools, but some features is paid. I like to use https://gwhois.org and Check-host.net
Great answer. Police and PIs use https://whoisology.com as well.Whois Tools, however if he have Whois Privacy you don't know who is behind the domain.
You can use Whois History to check previous domain transfer and information, let's think he had her domain without whois privacy, you can see it throught Whois History
If his whois is public you can search his/her email throught social media (using recover password) or mobile phone you will be able to discover whois.
That's the way who Police and private investigators discover most of guys behind some websites, also IP History is a good tool with Whois History.
But if he's a smart guy, probably is fake info.
For me the best tool is DomainTools, but some features is paid. I like to use https://gwhois.org and Check-host.net