The DNA of a Killer

USRY'S CASE, THEY SAY, WAS UNIQUE AND THE ONLY TIME THEY HAVE RECEIVED A FORMAL LEGAL REQUEST FOR D. N. A .- RELATED INFORMATION. AFTER WHAT HAPPENED TO USRY, ancestry. com TOLD US THEY TOOK ACTION; THE PUBLIC DATABASE USED BY AUTHORITIES WAS MADE PRIVATE AND CAN NO LONGER BE ACCESSED BY THE PUBLIC OR POLICE. BUT WE WERE WONDERING, COULD WHAT HAPPENED TO MICHAEL USRY HAPPEN AGAIN TO SOMEONE ELSE, WITH POLICE USING ANOTHER PUBLIC DATABASE? TO OUR SURPRISE, LAW PROFESSOR ERIN MURPHY SAYS MAYBE. >> YOU KNOW, THESE CASES TEND ONLY TO COME TO LIGHT WHEN SOMETHING GOES WRONG. >> Reporter: SO, YOU MIGHT NEVER KNOW IF POLICE CHECKED \ YOUR D. N. A. TO LOOK FOR A CRIMINAL? >> YEAH. MOST OF THEM DON'T HAVE TO TELL US, " HOW MANY TIMES HAVE YOU DONE THESE SEARCHES? HOW MANY PEOPLE DID YOU INVESTIGATE WITHOUT THEM EVEN KNOWING ?" >> Reporter: USRY DECIDED THE BEST WAY TO PREVENT IT FROM HAPPENING AGAIN WAS TO GO PUBLIC WITH WHAT HAPPENED TO HIM IN A DOCUMENTARY. HE WAS SHOCKED WHEN ANGIE DODGE'S MOTHER WAS WILLING TO TALK. WHAT HE DIDN'T REALIZE IS THAT CAROL DODGE HAD AN AGENDA OF HER OWN. >> SHE'S FAIRLY CERTAIN THAT A KILLER IS IN MY BLOODLINE. >> Reporter: DO YOU BELIEVE MIKE USRY IS RELATED TO THE KILLER OF YOUR DAUGHTER? >> SOMEHOW. >> Reporter: DESPITE ALL THAT, CAROL DODGE AND MICHAEL USRY HAVE FORGED A RATHER ODD CLOSE BOND. >> YOU'RE A REALLY SPECIAL PERSON. >> YOU ARE, TOO, CAROL. >> Reporter: AND AFTER HEARING CAROL AND ANGIE'S STORY, THE FOCUS OF USRY'S DOCUMENTARY CHANGED DRAMATICALLY, TO CAROL DODGE'S SEARCH FOR HER DAUGHTER'S KILLER. >> I THOUGHT THAT A BETTER, A MORE PRODUCTIVE THING TO DO WOULD BE TO TRY TO MAKE A FILM TO TRY TO BRING ATTENTION TO THIS. >> Reporter: USRY WANTED TO HELP CAROL, SO HE IMMERSED HIMSELF IN THE CASE, STARTING WITH THE MAN CHRIS TAPP. >> Reporter: USRY QUICKLY LEARNED THAT CHRIS TAPP WAS NOW CLAIMING THAT HIS CONFESSION WAS FORCED AND THAT THE IDAHO INNOCENCE PROJECT, HEADED BY THAT D. N. A. EXPERT, GREG HAMPIKIAN, WAS NOW WORKING TO SET TAPP FREE. BASED ON THE D. N. A ., IS THERE ANY WAY THAT CHRIS COULD'VE BEEN IN THAT ROOM? >> NO, NOT BASED ON THE D. N. A. >> Reporter: THE MORE CAROL DODGE LEARNED ABOUT D. N. A ., THE MORE SHE QUESTIONED CHRIS' CONFESSION, THAT HE HELD ANGIE DOWN WHILE SHE WAS BEING STABBED. >> IT WASN'T UNTIL I STARTED STUDYING SCIENCE THAT I SAID, " IT'S IMPOSSIBLE ." HOW COULD CHRIS ADMIT IN DOING WHAT HE SAID HE DID AND THERE BE NO PHYSICAL EVIDENCE? >> Reporter: BUT IT WASN'T JUST THE SCIENCE THAT BOTHERED DR. HAMPIKIAN; HE BELIEVES THAT CHRIS TAPP'S CONFESSION \ WAS COERCED BY THE DETECTIVES WHO INTERROGATED HIM. >> I WATCH IT, AND IT'S SO FRUSTRATING. >> Reporter: THIS IS CHRIS TAPP AT 40 YEARS OLD. HE'D BEEN INMATE NUMBER 56265 FOR 20 YEARS. >> YOU LOOK AT THAT 20- YEAR- OLD KID, YOU KNOW, AND YOU REALIZE, GOD, I WAS JUST AN IDIOT. >> Reporter: TAPP SAYS HIS CONFESSION WAS A LIE, A STORY FED TO HIM BY POLICE AND THEN FORCED BACK OUT OF HIM ON TAPE. >> YOU CAN SEE THEM SPECIFICALLY POINTING OUT FACTS TO ME, OR... OR GIVING LITTLE INNUENDOES... >> ... OR HINTS OF HOW THE MURDER WENT DOWN. >> Reporter: IT ALL BEGAN SIX MONTHS AFTER ANGIE'S MURDER, WHEN ONE OF HER FRIENDS, BEN HOBBS, WAS ARRESTED IN LAS VEGAS FOR SEXUALLY ASSAULTING A WOMAN AT KNIFEPOINT. NOW, IDAHO FALLS DETECTIVES HAD ALREADY QUESTIONED AND CLEARED BEN HOBBS, BUT BECAUSE THE CRIME HE COMMITTED IN VEGAS WAS SO SIMILAR, THEY WONDERED IF HE MIGHT BE ANGIE'S KILLER. AND SO, WHILE BEN HOBBS REMAINED IN CUSTODY IN NEVADA, DETECTIVES BROUGHT IN HIS BEST FRIEND FOR QUESTIONING, CHRIS TAPP. >> EMPHATICALLY, I SAID, " I HAD NOTHING TO DO WITH IT. I DON'T KNOW WHAT YOU'RE TALKING ABOUT ." \ I KNOW, THERE'S NO WAY. >> Reporter: BUT INSTEAD OF LEAVING IT AT THAT, TAPP COOPERATED. >> I FELT LIKE, " TRUST THEM, THEY'RE NOT GOING TO DO ANYTHING WRONG ." >> HE DOESN'T KNOW THEY CAN LIE TO HIM. MOST INNOCENT PEOPLE HAVE NO IDEA THAT THE INTERROGATORS CAN LIE TO YOU. >> Reporter: FIRST, TAPP WAS TOLD THAT THERE WAS IRREFUTABLE EVIDENCE THAT HIS FRIEND, BEN HOBBS, KILLED ANGIE DODGE AND THAT TAPP WAS THERE WHEN IT HAPPENED. >> Reporter: TAPP KEPT DENYING ALL KNOWLEDGE OF THE CRIME. >> Reporter: BUT DETECTIVES PERSISTED. AND EVEN THOUGH HE HAD A LAWYER, TAPP KEPT TALKING. AND SO, WHEN THEY OFFERED YOU A POLYGRAPH, SEEMED LIKE A GOOD IDEA? >> YEAH. SEEMED LIKE A GREAT IDEA. I HAD NOTHING TO HIDE, NO... NO REASON NOT TO DO IT. >> Reporter: BUT TAPP WAS TOLD HE WAS BEING DECEPTIVE. DETECTIVES PROMISED HIM FULL IMMUNITY, NO JAIL TIME, IN EXCHANGE FOR THE TRUTH AS LONG AS HE DIDN'T PARTICIPATE IN THE ACTUAL MURDER. THAT'S WHEN TAPP SAYS HE STARTED TELLING POLICE WHAT HE THOUGHT THEY WANTED TO HEAR. >> Reporter: TAPP TOLD DETECTIVES HE WAS THERE WHEN BEN HOBBS KILLED ANGIE DODGE. >> Reporter: THEN, JUST HOURS LATER, A SHOCKING TWIST-- DETECTIVES LEARNED THAT BEN HOBBS DID NOT MATCH THE KILLER'S D. N. A. TAPP WAS TOLD THERE WAS NOW EVIDENCE THAT A THIRD MAN WAS AT

JEREMY SARGIS, A FRIEND OF TAPP AND HOBBS. 90 MINUTES LATER, TAPP WAS BLAMING SARGIS FOR ANGIE'S MURDER. >> I CONTINUED TO LIE. I CONTINUED TO GIVE THEM STORY AFTER STORY. AND THEY SHOULD'VE JUST STOPPED, BUT THEY DIDN'T. >> Reporter: BUT CHRIS, WHY DIDN'T \ YOU \ STOP? >> I DIDN'T THINK I COULD. >> Reporter: DETECTIVES TESTED JEREMY SARGIS' D. N. A ., AND IT WAS ALSO NOT A MATCH. >> AND WHEN JER'S D. N. A. CAME BACK IS THE DAY THEY VOIDED MY IMMUNITY AGREEMENT, RIPPED EVERYTHING UP AND TOLD ME I'M THE HUMUNGOUS, YOU KNOW, LIAR. >> Reporter: THAT'S WHEN CHRIS SAYS POLICE PUSHED HIM TO CHANGE HIS STORY ONE LAST TIME. AFTER 23 DAYS AND SEVEN INTERROGATIONS, CHRIS TAPP CONFESSED TO PARTICIPATING IN ANGIE'S MURDER. >> THAT'S WHAT WAS THE END OF IT ALL. THAT'S WHAT BROUGHT ME TO PRISON. >> Reporter: AUTHORITIES HAVE REPEATEDLY DISMISSED TAPP'S CLAIMS OF A FORCED CONFESSION UNTIL 2016, WHEN A SHOCKING DISCOVERY WOULD CHANGE THE GAME. NEVER- BEFORE- SEEN VIDEOTAPES OF SEVEN POLYGRAPH EXAMS ADMINISTERED TO CHRIS TAPP, TAPES THAT CONVINCED EVEN CAROL DODGE THAT CHRIS TAPP IS INNOCENT. >> CHRIS TAPP BASICALLY JUST GOT RAILROADED. >> Reporter: CAROL DODGE TOOK ON A NEW MISSION TO FREE THE MAN CONVICTED OF HER DAUGHTER'S MURDER AND FIND THE KILLER WHO LEFT HIS D. N. A ., EVEN IF IT TURNED OUT TO BE A MEMBER OF MICHAEL USRY'S FAMILY. >> Reporter: AS MICHAEL USRY BEGAN LOOKING INTO THE ANGIE DODGE MURDER CASE, HE HAD PRECONCEIVED NOTIONS. >> " WHY WOULD YOU CONFESS TO SOMETHING THAT YOU DIDN'T DO? I WOULDN'T DO THAT ." >> Reporter: AND NOW, WHAT DO YOU THINK? >> THAT IT'S POSSIBLE, THAT ANYBODY COULD DO IT. >> Reporter: NOW, USRY BELIEVES THAT CHRIS TAPP \ WAS \ FORCED TO CONFESS TO A CRIME HE DIDN'T COMMIT, AND CONDEMNED TO A PLACE WHERE HE DOESN'T BELONG. >> YOU ALWAYS GOT TO HAVE A LITTLE FAITH, GOT TO HAVE A LITTLE HOPE. I HAVEN'T ACCEPTED THIS AS MY END. >> I CAN'T IMAGINE SPENDING ONE DAY IN PRISON, LET ALONE 20- PLUS YEARS. >> Reporter: MIKE HEAVEY IS A RETIRED SUPERIOR COURT JUDGE WHO BELIEVES SO STRONGLY THAT CHRIS TAPP IS INNOCENT, HE'S SPENT THE LAST FOUR YEARS TRYING TO HELP PROVE IT. WHEN YOU LOOK AT THE INTERROGATION VIDEOS, HE KNOWS NOTHING... >> ... AND HE STRUGGLES FOR DETAILS. >> WHY? BECAUSE HE WASN'T THERE. >> Reporter: HEAVEY RUNS A WRONGFUL CONVICTION PROJECT CALLED JUDGES FOR JUSTICE, AND TOOK ON TAPP'S CASE AFTER WATCHING THE INTERROGATION TAPES. >> Reporter: JUDGE HEAVEY BECAME CONVINCED THAT CHRIS TAPP \ HAD BEEN COERCED INTO CHANGING HIS STORY AN ASTOUNDING SIX TIMES AND KNEW THAT SOMETHING WAS MISSING. >> BECAUSE I WAS CONCERNED. HE WENT FROM ONE DAY SAYING... >> ... AND THE NEXT DAY... >> " I'M AT THE CRIME SCENE, AND I STABBED HER ." I COULDN'T SEE HOW HE MADE THAT JUMP. SO, I WENT BACK TO LOOK AT THE POLYGRAPH, AND MY JAW JUST DROPPED. >> Reporter: IN BETWEEN CHRIS' NINE INTERROGATIONS, DETECTIVES ALSO ADMINISTERED SEVEN POLYGRAPH EXAMS. ALL OF THEM WERE RECORDED, BUT NO ONE HAD EVER BOTHERED TO LOOK AT THE TAPES, BECAUSE POLYGRAPHS ARE INADMISSIBLE IN COURT AND THE SOUND IS BARELY AUDIBLE. >> POLYGRAPHS ARE TYPICALLY USED TO ASSESS THE CREDIBILITY OF THE WITNESS, WHEN THEY'RE DONE HONESTLY. >> Reporter: AND HOW WAS THE POLYGRAPH USED IN THIS CASE? >> THIS CASE, IT WAS USED TO TRICK CHRIS TAPP INTO GIVING FALSE TESTIMONY. MY POLYGRAPH EXPERT SAYS IT WAS USED LIKE A PSYCHOLOGICAL RUBBER HOSE. THEY BEAT HIM UP WITH THE PSYCHOLOGY OF IT ALL TO COERCE HIM INTO FALSELY ACCUSING OTHER PEOPLE. THEY MANUFACTURED TESTIMONY TO GET HIM TO IMPLICATE HIMSELF IN THE MURDER OF ANGIE DODGE. >> Reporter: JUDGE HEAVEY SAYS THAT DETECTIVES IN THIS CASE BROKE THE RULES IN THE POLYGRAPH ROOM AND THOUGHT NO ONE WOULD EVER NOTICE. >> THE UNITED STATES SUPREME COURT HAS HELD THAT IT'S IMPROPER TO THREATEN. YOU CAN'T THREATEN BECAUSE IT LEADS TO FALSE CONFESSIONS. THEY THREATENED HIM WITH THE GAS CHAMBER, BEING ACCESSORY TO MURDER AND BEING A CONSPIRATOR TO MURDER. >> THEY FIGURED NO ONE'S LOOK AT THE POLYGRAPHS, SO IT'LL BE HIDDEN; NO ONE WILL EVER SEE IT. >> Reporter: HEAVEY SAYS CHRIS TAPP WAS BRAINWASHED. >> CHRIS TAPP EVENTUALLY COMES TO BELIEVE THAT THE POLYGRAPH IS AN ALL- KNOWING SCIENTIFIC INSTRUMENT THAT CAN READ HIS SUBCONSCIOUS AND IS TELLING THE MACHINE THAT HE WAS AT THE CRIME. >> CHRIS FINALLY SAYS, " YES, I STABBED HER BECAUSE BEN THREATENED ME ." AND THEN, CHRIS

>> THE POLICE OFFICER WALKS OVER AND SAYS, " GIVE ME YOUR HAND ," LIKE HE PASSED THE POLYGRAPH. AND THAT GETS CHRIS TAPP 30 YEARS TO LIFE, CHARGED WITH THE DEATH PENALTY. UGLY STUFF. >> Reporter: DO YOU REMEMBER THAT MOMENT? >> YEAH. YEAH. SCARED. SCARED. THAT'S PRETTY MUCH THE DAY MY LIFE ENDED. >> Reporter: BUT TAPP NEVER TOLD ANYONE WHAT HAPPENED DURING THOSE POLYGRAPH EXAMS. >> I DIDN'T KNOW WHAT THEY DID IN THE POLYGRAPH TAPES WAS WRONG. I DIDN'T KNOW. IF I WOULD'VE KNOWN THESE THINGS 20 YEARS, 15, TEN YEARS AGO, THEN MAYBE WE WOULDN'T BE HERE TODAY. >> Reporter: IDAHO FALLS POLICE DENY ANY WRONGDOING IN THEIR INTERROGATIONS OR POLYGRAPH EXAMS. DO YOU THINK THE POLYGRAPH WAS USED AS A COERCIVE TOOL? >> WELL, I DON'T KNOW THAT WAS THE INTENT. I THINK THE INTENT IS TO FIND OUT THE TRUTH. >> Reporter: OVER THE YEARS, THE COURTS HAVE UPHELD TAPP'S CONFESSION AS VALID AND ADMISSIBLE, AND NOT THE PRODUCT OF COERCIVE POLICE CONDUCT. >> I DON'T THINK THEY WERE TRYING TO CAUSE HARM. THERE WASN'T ANY MALICIOUS INTENT, I DON'T THINK. >> IT'S HARD FOR ME TO WRAP MY HEAD AROUND WHAT THE POLICE ARE THINKING. >> Reporter: JOHN THOMAS IS CHRIS TAPP'S APPELLATE ATTORNEY. >> IT'S OKAY. YOU MADE A MISTAKE. JUST SAY, " HEY, I MADE A MISTAKE. WE GOT THE WRONG GUY ." LET'S ALL RALLY AROUND AND LET'S GET THE RIGHT GUY. >> Reporter: MIKE HEAVEY WAS HOPING THAT THE NEWLY DISCOVERED POLYGRAPH TAPES WOULD BE ENOUGH FOR A JUDGE TO GRANT CHRIS TAPP A NEW TRIAL. >> THOSE POLYGRAPH VIDEOS ARE NOW NEW EVIDENCE. THEY'RE THE WEDGE TO GET CHRIS IN FRONT OF A JUDGE TO SEE THE COERCION THAT WENT ON. THE POLYGRAPHS ARE THE ANSWER TO GETTING HIM OUT. >> Reporter: WHAT'S YOUR BIGGEST FEAR WHEN IT COMES TO THIS CASE? >> (\ SIGHS \) I GUESS MY BIGGEST FEAR OF THIS ENTIRE CASE WOULD BE THAT IT JUST CONTINUES ON, INDEFINITELY. CHRIS STAYS IN JAIL, CAROL CONTINUES TO SEARCH. >> I HOPE HE WALKS OUT A FREE MAN. >> Reporter: IT'S NOT OFTEN YOU HEAR THE MOTHER OF A VICTIM SAY THAT ABOUT THE ONLY MAN SERVING TIME FOR HER DAUGHTER'S MURDER. >> TRUE. >> Reporter: FOR THE FIRST TIME EVER, MICHAEL USRY WAS ABOUT TO COME FACE- TO- FACE WITH THE MAN CONVICTED OF KILLING ANGIE >> CHRIS. >> Reporter: CHRIS TAPP. >> LET ME JUST TAKE A MOMENT, BECAUSE I DIDN'T THINK THAT THIS WOULD EVER HAPPEN. >> Reporter: AND INTERVIEW HIM FOR HIS DOCUMENTARY. >> WHY... WHY DID YOU CONFESS? >> TO GIVE THEM WHAT THEY WANTED, TO GET AWAY FROM THEM, TO DO WHATEVER IT TOOK FOR ME TO GO HOME. >> Reporter: THE DAY USRY MET CHRIS TAPP, HE WAS ONLY WEEKS AWAY FROM TWO HEARINGS THAT HIS LAWYER, JOHN THOMAS, HOPED WOULD SET HIM FREE. >> WE HAVE TOO MUCH EVIDENCE SHOWING THAT CHRIS TAPP WASN'T THERE. >> AND I'M INNOCENT. >> Reporter: HAVE YOU EVER FOUND D. N. A. THAT MATCHED CHRIS TAPP AT THE SCENE? >> NO. >> Reporter: FORMER POLICE CHIEF MARK McBRIDE MAINTAINS THAT GIVEN TAPP'S CONFESSION... >> Reporter: ... THE ABSENCE OF HIS D. N. A. AT THE CRIME SCENE PROVES NOTHING. THEN, A STUNNING TURN OF EVENTS. THE DISTRICT ATTORNEY'S OFFICE WANTED TO MAKE A DEAL. TAPP'S MURDER CONVICTION WOULD STAND, BUT THE RAPE CONVICTION WOULD BE EXPUNGED AND THERE WOULD BE NO PROBATION. >> CHRIS TAPP WOULD JUST TAKE HIS LUMPS ON HIS 20 YEARS AND... AND WALK... WALK A FREE MAN. >> Reporter: UNWILLING TO RISK ANOTHER TEN YEARS IN PRISON, TAPP TOOK THE DEAL. >> THERE WERE TOO MANY WHAT- IFS. WE HAD HAD A NUMBER OF POST- CONVICTION PETITIONS BEFORE, AND ALL OF THEM HAD BEEN DENIED. >> Reporter: THE NEXT DAY, A " 48 HOURS" PRODUCER FOLLOWED JOHN THOMAS AS HE SPED TO THE COUNTY JAIL, PAPERWORK IN HAND. >> WE ARE HEADED TO THE JAIL TO GET CHRIS TO REVIEW THE PLEA AGREEMENT. AND, IF HE REVIEWS IT AND AGREES WITH IT, I WILL SIGN IT AND... AND HE'LL BE OUT OF PRISON FOR THE REST OF HIS LIFE. >> Reporter: WHAT HAVE YOU GOT THERE? >> GOT IT SIGNED, SIGNED AND SEALED. IT'S ALL GOOD. >> Reporter: 48 HOURS LATER, TAPP SUPPORTERS GREG HAMPIKIAN, MIKE HEAVEY AND EVEN MICHAEL USRY HAD MADE IT TO IDAHO FALLS FOR AN EMERGENCY HEARING. >> NERVOUS. >> Reporter: A LITTLE OVER TWO DECADES FROM THE DAY CHRIS TAPP WAS FIRST ARRESTED, HE WALKED INTO THE COURTROOM ONE MORE TIME IN HANDCUFFS. >> ALL RISE. THIS COURT IS NOW IN SESSION, THE HONORABLE ALAN STEPHENS PRESIDING. >> Reporter: AND AFTER SOME LEGAL FORMALITIES... >> DID YOU READ THE STIPULATION, EVERY LINE OF IT, BEFORE YOU SIGNED IT? >> YES, YOUR HONOR. >> Reporter: ... CAROL DODGE WAS CALLED ON TO MAKE A VICTIM IMPACT STATEMENT ON BEHALF OF HER DAUGHTER, ANGIE. >> GO AHEAD, MS. DODGE. >> I STAND HERE TODAY NOT AS A VICTIM, BUT I AM A SURVIVOR OF A HORRIFIC CRIME THAT TOOK MY DAUGHTER'S LIFE. >> Reporter: CHRIS TAPP FOUGHT BACK TEARS. >> AND I HOPE THAT YOU WILL HELP ME FIND JUSTICE FOR ANGIE. >> Reporter: BUT IT WAS CLEAR THAT ALONG WITH HER DAUGHTER, CAROL CONSIDERS CHRIS TAPP ANOTHER VICTIM IN THIS ENDLESS TRAGEDY. >> I'M EXTREMELY HAPPY FOR YOU THAT YOU HAVE YOUR LIFE BACK. >> MR. TAPP? >> Reporter: BUT THE JUDGE STILL HAD TO SIGN OFF ON THE DEAL. AND THEN, WITH JUST A FEW WORDS... >> AND I DO ACCEPT THE STIPULATION. >> Reporter: ... JUDGE ALAN STEPHENS SET CHRIS TAPP FREE. (\ APPLAUSE \) CHRIS' HANDCUFFS WERE REMOVED, AND CAROL DODGE WAS THE FIRST TO HOLD HIM IN HER ARMS. JUST FEET AWAY FROM THE CELEBRATION... >> VICTORY! >> VICTORY! (\ CHEERS AND APPLAUSE \) >> Reporter: ... THE HUNT FOR ANGIE DODGE'S KILLER CONTINUED. >> I GOT A TAP ON THE SHOULDER FROM ONE OF THE BAILIFFS, AND HE SAID THAT DETECTIVE McKENNA WANTED TO TALK TO ME. >> Reporter: DETECTIVE McKENNA SHOWED MICHAEL USRY THIS SKETCH OF ANGIE'S KILLER. IT WAS MADE WITH NEW TECHNOLOGY THAT CLAIMS TO RECREATE FACIAL FEATURES USING D. N. A. >> WHEN HE SHOWED ME THE SKETCH, THERE WAS A SPLIT SECOND WHERE I REALLY HAD THIS FEAR THAT I WOULD ACTUALLY RECOGNIZE THIS PERSON. >> Reporter: BUT MICHAEL USRY WAS, ONCE AGAIN, A DEAD END. IT WAS NOT A FACE HE KNEW. >> THERE WAS A LITTLE BIT OF RELIEF WHEN I SAW THE COMPOSITE SKETCH BECAUSE I HAVE NEVER BELIEVED THAT SOMEONE IN MY FAMILY COULD BE INVOLVED IN A CRIME LIKE THIS. >> IT'S HIGHLY LIKELY THAT HIS FAMILY HAS NOTHING TO DO WITH THIS CRIME AT ALL. >> Reporter: WHILE POLICE STILL BELIEVED THAT USRY'S FAMILY TREE CONTAINED A KILLER, LAW PROFESSOR ERIN MURPHY DISAGREED. >> 99 % OF PEOPLE MATCH TO ONE ANOTHER ON THE GENOME. SO, I WILL MATCH SOMEONE WHO LIVES ON THE OTHER SIDE OF THE GLOBE, WHO HAS NO DIRECT GENETIC CONNECTION TO ME WHATSOEVER, JUST BECAUSE WE ARE HUMAN BEINGS. SO, WHAT'S REALLY IMPORTANT TO ASK IS, " WHAT'S THE QUALITY OF THE MATCH? HOW MUCH INFORMATION DID YOU LOOK AT ?" >> Reporter: AS IT TURNS OUT, PROFESSOR MURPHY WAS RIGHT. ON WEDNESDAY, JULY 12, 2017, IDAHO FALLS POLICE PUT OUT THIS PRESS RELEASE STATING THAT THEY " TOOK THE D. N. A. TESTING TO THE NEXT LEVEL" AND " RECENTLY RECEIVED A D. N. A. REPORT THAT CLEARS MICHAEL USRY, JR ., AND HIS FAMILY OF INVOLVEMENT IN THE ANGIE DODGE HOMICIDE CASE ." THE REPORT FROM THE D. N. A. LAB ALSO STATED THAT THEY WERE 87. 63 % CONFIDENT THAT THE UNKNOWN D. N. A. FROM THE ANGIE DODGE CRIME SCENE DID NOT MATCH THE USRY FAMILY. CAROL DODGE MUST NOW FIND THE STRENGTH TO KEEP GOING. >> YOU HAVE TO BE REALLY STRONG TO CONTINUE THE JOURNEY TO JUSTICE. >> I DON'T KNOW HOW SHE GOES ON, AND YET I CAN UNDERSTAND HOW SHE COULD NEVER QUIT. >> Reporter: CAROL IS WORRIED THAT POLICE WILL NEVER CATCH ANGIE'S KILLER IF THEY REMAIN FOCUSED ON \ THEIR \ THEORY OF THE CRIME, THAT CHRIS AND TWO OF HIS FRIENDS KILLED ANGIE. >> I HOPE THAT THEY CAN NOW GO FORWARD AND GET OUT OF THE CHRIS TAPP BOX AND STOP LOOKING FOR TWO TO THREE PEOPLE WHEN WE JUST HAVE ONE D. N. A. THAT'S ALL WE'VE GOT, IS ONE D. N. A. >> Reporter: EVERYONE INVOLVED IN THE CASE HAS VOWED TO NEVER STOP SEARCHING FOR THE MAN WHO MURDERED ANGIE DODGE, EVEN THE YOUNG FILMMAKER ONCE SUSPECTED OF BEING HER KILLER. YOU COULD'VE WALKED AWAY. >> AND I PROBABLY WOULD HAVE. I CONTINUE TO STICK WITH IT BECAUSE... MAINLY BECAUSE OF CAROL DODGE. I WANT TO HELP HER. I LOVE CAROL. WE'RE IN IT TOGETHER. Captioning sponsored by CBS Captioned by Media Access Group at WGBH access. wgbh. org >> WHAT ARE YOU DOING TODAY? >> ABOUT TO JUMP OUT OF A PERFECTLY GOOD AIRPLANE. >> JUMPING OUT OF A PLANE! >>\ A YOUNG MOTHER VANISHES... >> WOULD SHE HAVE EVER LEFT HER KID? >> OH, NO. >>\... AS A DEADLY HURRICANE \ HITS. >> POLICE ARE SEARCHING FOR A TEXAS MOTHER WHO MYSTERIOUSLY DISAPPEARED BEFORE HARVEY HIT. >>\ WAS IT THE PERFECT STORM FOR \ MURDER? >> WEATHER AND TIME DETERIORATE PHYSICAL EVIDENCE. >> CRYSTAL McDOWELL'S CAR WAS FOUND SUBMERGED IN THIS MOTEL 6 PARKING LOT. >>\ ACCESS INSIDE THE \ INVESTIGATION. >> I'VE BEEN A LAWYER FOR 24 YEARS AND I'VE BEEN A PROSECUTOR FOR 22. I'VE NEVER SEEN ANYTHING LIKE THIS, COUPLED WITH THE STORM. >>\ THREE PERSONS OF INTEREST. >> I ASKED HIM, " DO YOU KNOW WHERE THE BODY IS ?" AND HE JUST, LIKE, LOOKED AWAY FROM ME AND JUST, LIKE, BALLED HIS EYES OUT. >>\ NEXT. >>\ CBS NEWS, ORIGINAL REPORTING.