just report it to the staff by using the link down  below "Help and Support"

It would have been better to just file an abuse report.

If you wish to know more about proper cheater detection, join the cheating group and read stevecollyer's threads on top 3 match ups.

Chess.com likes to sequester all the cheating conversation there.

If I understand you correctly, you were checking his moves on a chess engine while you were playing, because you suspected him of cheating?

And I just checked. You won 7/9 games shown. Looks like you were cheating.

 you should be a detective

I am a little bit confused with your post. You mention a cheater but you do not name and shame - what is the name of the person so that I can block this person from playing chess against me? Where are the games to analyze to confirm your suspicions?

no name should be mention here, is the chess.com's policy.