I don't believe that they deliberately overdosed her or drugged her. But reading between the lines, here is what I think likely happened: Multiple articles said she was in pain in the past year due to nerve issues in her back. Hayden had openly been a survivor of addiction - which means doctors probably refused to prescribe her painkillers. Witnesses from the property reported that when EMS was trying to revive her, Brian's brother was hysterical, while Brian didn't become emotional until they told him she was deceased. Other articles noted that Hayden's pills were found in a baggie - not a prescription bottle. So to me, it seems like Hayden was in pain and couldn't get meds, but Brian or his brother had access to pills off the street. Pills off the street are extremely dangerous because they often contain fentanyl or are highly potent compared to prescription drugs. They knew there was a risk due to them not coming from a legit source, which is why they kept Narcan at the home. Hayden probably took an amount she was used to taking in the past but if the pills were counterfeit, the content of opioids in them was too high. Regardless of whether Brian or his brother knew the pills were counterfeit, either of them could end up being charged with crimes that carry 20-30 years in prison if it is determined they sold or distributed the pills that resulted in her death. It would be surprising if her access to the pills were not through one of them, since they were from SC and I can't see Hayden risking her career by smuggling pills through the airport. LE's investigation into "criminal conduct" is likely all about where the pills came from and who supplied them to her instead of whether she was drugged involuntarily.