. >> i put a whole new wardrobe, low-cut blouses, push-up bra.ad to try to attract him. >> capturing secret recordings. >> could those conversations help set her son free? >> "nightline" will be right back. back. we only have 30 seconds to describe the newest specialty flavor in the signature crafted recipes collection by mcdonald's: garlic white cheddar. it's layered with a slice of smooth, perfectly melty, white cheddar cheese. a crunchy medley of tasty, crispy garlic chips... a dramatic drizzle of smooth, delicious and flavorful, delectably creamy garlic aioli... all coming together with a mouthwateringly juicy tomato slice and crisp iceberg lettuce atop crispy buttermilk chicken on a soft, warm artisan roll. (breath) luckily, you can take all the time you need to savor every bite. the signature crafted recipes collection, by mcdonald's. ♪ >>> good evening. we begin with breaking news about backpage.com. that classified ad website known for facilitating sex trafficking. tonight it appears authorities are cracking down. backpage.com, once worth

. >> low cut blouse, push-up bra, high heels. secretly recording, trying to catch him. >> and not just the juror putting the prosecutor in her crosshairs. >> i have never lost a homicide case. >> oh, god. you know why? because she is a cheater. >> just weeks ago a bombshell game changer for the mother who put her own life on hold to live a double life for her son. is there any way you're blinded by your mother's love? >> i have been begging for a fair trial. just give me a fair trial. >> undercover mother. i'm elizabeth vargas and this is "20/20." here's "nightline"'s juju chang. >> good morning. >> are you ready? >> i am. rikers, here we go. >> rikers here we come. what a cheery place to visit huh? >> reporter: doreen quinn giuliano has become all too familiar with one of the country's most dangerous and notorious jails. >> it's out of control. it's um, very violent between the inmates and the guards. you don't know who to trust. >> reporter: every week, she makes the hour-long drive from her home in brooklyn to rikers island to