I'm playing now. Once you've completed a gold badge you pay 10,000 coins to unlock a platinum badge. I'm on Episode 10 but have gold & platinum badges for Episode 1-9.
Comment found on CSI: Hidden Crimes: How do I get platinum...
You have to finish all 61 gold badges first and then you will be able to complete all the episodes again for 61 platinum badges.
Comment found on CSI: Hidden Crimes: How do I get platinum...
Yes, you should be able to earn platinum badges in all episodes.
Comment found on CSI: Hidden Crimes: Can you earn a platinum...
I've heard someone else say they were doing the platinum badge, but I finished all 45 stars yesterday and it's not giving me the option to move to the platinum round
Comment found on CSI: Hidden Crimes: Can you earn a platinum...
To Earn a Platinum Badge, first you earn a Gold Badge (by filling all the gold stars in a chapter), then spend 10,000 coins for the premium mode and fill all the silver stars. I find it's a great way to store up a lot of energy. Each silver star can be exchanged for 20 energy when you need it.
Comment found on CSI: Hidden Crimes: how do you earn a platinum badge
How do you get a platinum badge?
Comment found on CSI: Hidden Crimes - Episode 6: Murder on the Set