>> did names pop up? >> yes. >> their real names, aaron lewis and his wife, crystal lowrie. police raced over to put the couple's house under surveillance. >> this was a very delicate operation. >> yes. we were working with the expectation with the hope that she was still alive. >> detective allison said he wasn't sure if the couple was even involved. they wanted to see what he looked like. remember the eyewitness had seen a skinny man with short brown hair the night beverly disappeared. they hadn't been there long when a man matching that description walked out the door but this didn't approach him. >> were you hoping he would lead to you beverly? >> yes. we felt if we made contact too early, if he was the one we were looking for, everything is shot. >> louis got into his car and the plan fell apart. >> he saw us sitting there. that's when he started speeding off.