Transcript for Prince suddenly dies at Paisley Park from fentanyl overdose: Part 2
l'eggo your Eggo Repter: On the April 21st, 2016, a man walks up to the front door of one of esota's Lamark sites, paisley pathe home oce. His name is Andrew Kornfeld, and oninent rehaerapist inaliforni on his way to treat prince. Andrew kofeon a red eye from California to the twin he wants to talk to prince and E if he can convince prince get clean off the opiates that he seems to be on.orter: Butn as Kornfeld wts inside Isley park to meet prince, in an most shakeeady, the 57r old supetar's de Bos found onhet ton evator. THAs the thg ths your hea. Prince almost got the help he Ed, but heid we're coming on the ah breaking news that has Ed. W do know THA prince found sponsive at H estate innesota. R: The stuing news of prince's untimely death hits public like seismic shockwaves of grief and sbsh over th legendary mer's legion of fa over the world. Ow did F when you heard the news today? Evastating. It was just horrifying. You're talking about the most talented pop musician of his era. A guwho had the most astonishing assortment of atr seen. Rter: That tall dilahiic performance at the rock and rollhall of fa. People danced, fell inov greatest nights of their lives wating prince perfor the idea that he wouuccumb to the same thing that had taken so many her artists, that was ki Reporte that deep sorrow and concernhat caused his death, ever proud among his close family and friends. I just dn't believe it happened, to tl you the H. Repor in a rare interview, ps R Sharon Nelson agreed to sit down with "20/20." Did you T H Musi Oh, no Reporter: Tok a her ecical sibli he played the piano when he was 5. My D would say, "Boy, St pounng on those keys!" This is a gift, Bob. Not many aorn with I B god blessed hit that gi. Eporter: Sharon says her lf-brother'sden death a complete mystery to his family. He something athe last party he gave. Heaid, "Don'ay for me T. I'm all right." And monday or twoays late he W Reporr: To get the bottomthat myste, police go throughry room ofhe once off-lits estate. D they finbottles Ed with pills bearing that stamp reme, those were the same opioid pills him during that overdose crisis in Moline. Hhaof pills at were scattered around and the Watson 853 is stamped on the pills. Anso watso3 can be a legitimate pain reliever, Milar to vod Reporter: But then,uge shock, the coroner's report comes oud reveals at, in fa, die from an overdose but thculprit wasomething that took everyone by surprise, a drug called fentanyl. What was your re realizt fentanyl? Well, I looked it up. I had O Google I what is this drug?at is it? I had no idea. Of the U.S. Dg enforcemt agency outside Washington, D.C. Fenta wl a synthetic io it's a vstrong paiever. Reporter: Fentanyl is legally prescribed in patches to TRE oplering severe pain, like endstage cancer patients. It'sently madeeanew way tocute crimils Fenl is about 3 50 times mortent than heroind just as example two milligrams of fentanyl would be conred for Mo O population a lethal dose. Reporter: But that begs the question. How in the world did pri obtain this incred powerful drug? The startling answer came after vestigatorteaming of thoills confiscated at paisley Pait was revled that they were nolegitimaterescription painkillers at all. They're acalerfeits, lad with fnyl instead of the real ingredient. That "Watson 853" imprint, a compleake. Ilooks the as a regular pi. And, see, 'S the dan of because U ow what you're gngu' a potential D pill kill you. He wouldn't haven like tt at all, D he known. If you're king it fo pain, then you think you're gonna get healed, and you're not. U're gonnaie Rr: And it'no many other unsuspeing icallen preyo black et counterfeit pilninystead of the acalt. Everything from fake painkille pis like oxycodond rco xanax, an anti-anxiety med T by llions. There'smathat E dying of thing. Atever it Y 're putting it out there. Rtegi involving countet xanax the beautiful as of Santa uz, here, tosh Ackerman grew up an all-americ bpassion for littleeague basell tosh was St Gerson, veryind-hearte very gene. Reporter: In October 2015, a friend g29-year oltosh a xanax pill after he said he was having trouble sing. This is H room. Reporter: The nex morn his mother Carrie tosh was ve in his bedroom. They tried everything the could Tim, but it was way O late. The long it still ds. The rest my life without H Reporter: An autopsy revealed that, juste Ince, tosh haddied of a ssive fentyl erdose. Ax pill, ather one of ose fake pls laced wh fentanyl. Was so toxic that tosh died despite taking less than half of the pill. It's Russian roulette. Yove no ideaf this pill is one of those or not. He did not plan to die that night.he had hishoea wanted mor eporter: Tt friend, O gave tosh the counterfeit xanax, warested aft trying to dump the pills by the side of a road he plead was sentenced to a year in prison. But what rns unknown- where the poisonls came from, and more importantly, who Mam. You' faith the ones that actually manufactured these pills -- Oh, Y. Yes. Itreed, justut D. Thosere the peoe O need to be held accountable. You're poisoning people ultimatehat you'reoi Reporte same mystery tormenting prince's family. More than two years after prince'sth, authories came fromou have any idea these pills --se pills came from atsoever. They don cves
This transcript has been automatically generated and may not be 100% accurate.