is that a little jolt, melvin roberts is the victim? yeah, because melvin is not the type of a person to be a victim of anything. andrea canning: melvin was the longest practicing lawyer in south carolina. he had defended both the rich and poor for 55 years. he almost sounds like a bit of a small-town celebrity, whether he liked it or not. the thing about melvin is he was in to everything. andrea canning: he was so influential, the street where he lived was named after him, roberts avenue, a true renaissance man devoted to his family. he was everything to me. he was my best friend. he was my mentor. andrea canning: melvin had two sons, david and ronnie. he was instrumental in making me into who i am. andrea canning: the three men shared an unusually strong bond. dad, david, and myself, it was our normal routine to have lunch every day. you all sound thick as thieves, the three of you. absolutely. the last thing i did every day before i went out was i'd give dad a big hug and a kiss on the cheek and tell him i loved him. and he'd tell me

craig melvin: a lovers triangle, a circle of friends. was one of them a killer? robert lopez: this was planned. this was on purpose. erika friman: how could you do something so horrific? craig melvin: hello and welcome to dateline. high schoolers erika friman, pedro bravo and christian aguilar were like three peas in a pod. after graduation, they even picked colleges in the same city. then one of them went missing last seen in a dangerous area of town. as the hours passed, the mystery deepened. then, investigators uncovered a hidden truth one, they believed, might be a motive for murder. here's dennis murphy with "circle of friends." dennis murphy: remember going away to college? maybe your first time away from home? there were new friends waiting to be made. the tingling of possibilities. erika friman: oh, god. the first kiss was amazing. dennis murphy: sometimes disappointments when things didn't work out. robert lopez: i thought he was just depressed. we just didn't take it that seriously. and you know, maybe we should have. dennis murphy: for three florida teenagers

andrea canning: for melvin's family, only partial justice has been served. ronnie roberts: i will not give up until we know everybody that was involved. and what that son of a bitch needs to understand is it's going to be a lot easier on them if they come forward instead of the police having to find them. david roberts: i always say, tick tock, clock's ticking. andrea canning: you're coming? we're coming. ronnie roberts: we sure is. david roberts: and we ain't giving up. that's all for this edition of "dateline." i'm craig melvin. thank you for watching. . i'm craig melvin. and i'm natalie morales. and this is "dateline." thin a number of minutes. dizziness, confusion, weakness. those are your clues. you're looking for anything that could possibly contribute to the person's death. one dose, a high enough dose, could do all of that. craig melvin: she found love at last with husband number three, the charming "jeopardy" champ. he belonged to mensa. mary siebold: younger guy, gourmet cook, nuclear physicist. i was impressed. craig melvin: then suddenly, she was gone, a myster

craig melvin (voiceover): coming up a new direction, a new suspect and finally an arrest. robertole package right there, so it's all right in a nutshell. and that's what says, hook him. craig melvin (voiceover): when dateline continues. when you live with diabetes, progress is... having your coffee like you like it without an audience. ♪♪ [silence] the freestyle libre 3 plus sensor tracks your glucose in real time so everyone else doesn't have to, and over time it can help lower your a1c confident choices for more control of your life. this is progress. learn more and try for free at freestylelibre.us ♪♪ gold bond believes touch says everything. it says... i see you. i feel you. and...i know you. gold bond. get in touch with irresistibly touchable skin. veggies from my boy junior. what are we doing here? anybody asks? we were at grandma's. >> just because it's wet outside, you don't need to wear boots. >> presenting skechers waterproof sneakers with rugged, 100% waterproof construction in a comfy, breathable, lightweight, easy to wear sneaker. ditch the boots and experience comfy