Most claims made by this website come from a court filing from Perry's murder case called "STATE'S NOTICE OF INTENT TO INTRODUCE EVIDENCE OF EXTRANEOUS CONDUCT". The copy hosted by this site was uploaded to PDFCoffee by the Houston Chronicle, but if you doubt the document's veracity you can find a scanned version on the Legislative Reference Library of Texas website.
You can also find reporting on the document from The Texas Observer and The Houston Chronicle.
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