Spivey wrote in the affidavit: "I am familiar with other items of fact developed during this investigation that have not been placed in the public record to support a search warrant and, in my opinion, this evidence ... indicates that Jason Young was the perpetrator."
Search warrants and affidavits in the case detail damning circumstantial evidence against Jason Young, including alleged extramarital affairs and a bottle of extra-strength adult Tylenol police believe was given to Cassidy to make her drowsy during her mother's murder.
Police also noticed an adult shoe print that they said was from a size 12 Hush Puppies Orbital shoe, which was left in the bloodstains. Police later found through store records that Jason Young had purchased a pair of size 12 Hush Puppies Orbital shoes more than a year before his wife's death, according to investigators' reports.
Records seized from Jason Young's computer turned up search queries on "anatomy of a knockout," "head trauma knockout," "divorce" and "gay bars in New York City," according to police affidavits.
There were also searches for "right posterior parietal occipital region" -- the occipital region is in the back of the head -- and "ischemia," the decrease in the blood supply to parts of the body caused by constriction or obstruction of blood vessels, according to the affidavit.
According to police affidavits dated Feb. 13, 2008 and Nov. 6, 2008, Jason Young checked into a Hampton Inn in Virginia the night before his wife's body was found and had been having an affair. He was seen on hotel security cameras the night before his wife's body was discovered wearing two different sets of clothing within a few hours, authorities said.
Phone records show about 980 cell phone calls and text messages were sent between Jason Young and his alleged mistress between Oct. 4 and Nov. 3, 2006.
On Oct. 28, 2006, days before the murder, Jason Young e-mailed the woman he'd been seeing: "i don't know how all this happened, but i know how it will end up … two broken hearts … but, i don't care. i know there is pain in my future, but you are so worth it, even if it's only for a 'blink' in time."