so he went directly to pink skirt.s like-- this is the first time he's seen somebody with a similar description to the assailant. narrator: when the man refused to answer the detective's questions, he was arrested on the spot for suspicion of murder. his name was jonathan román. and he lived in la perla. he had no criminal record. narrator: the 22-year-old denied killing or even knowing adam. but when he was picked out of a photo lineup by one of the eyewitnesses who was a lawyer, it was enough for the authorities. román was charged with adam anhang's murder. when you heard jonathan román had been arrested, did you think, oh, sense of relief, finally. oh, yeah, of course. natalie morales: they caught a guy. sure. narrator: román pleaded not guilty and was released on bond. jonathan roman: [non-english speech] interpreter: i am not a murderer. narrator: he spoke with "dateline" in 2007 as he awaited trial. jonathan roman: [non-english speech] interpreter: i don't have anything to hide. i'm innocent. narrator: román said

and i'm like, oh, that's the pink skirt murder.e, and it became agent patterson's top priority case. one of the first things he did was call abe. i remember like the first phone conversation i had with him and just still the grief in his voice. yeah. like, that cut me. narrator: he made a promise to abe. i told him, whatever it takes, like, we will get her. narrator: but agent patterson didn't yet fully understand who he was up against. urea was in italy and untouchable. the fbi's hands were tied. abe's however, were not. the fbi did a tremendous job. i mean, they did an incredible job. but they don't have jurisdiction in italy. so i had to go out and hire at my expense and everything else, the investigators in italy. narrator: abe refused to wait for urea to trip up. he hired private investigators to keep tabs on her and report back to him. abe would put off his own retirement so he could fund his investigation. and it had to be done because no one else was doing it. narrator: abe's investigators surveilled urea. these pictures of