you were finally gonna catch derek alldred? we were ever gonna catch him. >> reporter: the pick up time was fast approaching. derek sent a text to tracey. >> there was a problem. >> best laid plans don't always work the way they're supposed to to? >> they don't. >> reporter: tracey has bad news for law enforcement. >> was she frantic? >> she was a little frantic and we were more concerned with losing him. >> reporter: and derek finally in custody claiming he is the victim of a scorned woman. >> when things went south, i mean, she was bitter. and wanted revenge or whatever you wanna call it. >> when dateline continues. at carvana, we treat every customer like we would treat our own moms, with care and respect. to us, the little things are the big things. which is why we do everything in our power to make buying a car an unforgettable experience. happy birthday. thank you. we treat every customer like we would treat our own moms. because that's what they deserve. >>> reporter: the navy's sting operation in fort worth was in troubl

. >> i googled derek alldred and i see all his old mug shots. >> when i saw the uniform i knew that thereeally wrong because he had a fake batch on. >> every minute he is with you, he is stealing all of your money. the more we found out about him, the more dangerous he became. >> he is starting to brandish