Documentary "Rape on the Night Shift," produced by Frontline, is a collaborative investigation into the vulnerabilities, sexual abuse and dangers faced by undocumented, Hispanic and immigrant women when working in janitorial services during the night shift. The documentary, airing in three parts, presents the testimonies of 21 women, governmental efforts, and undercover operations to expose predators.

Nearly 1-in-5 women and 1-in-71 men have been raped in their lifetime, and 12 percent of rapes or sexual assaults happen to women while they're at work. According to the Justice Department, there are more than 17,000 sexual assaults at work each year.

The fact-finding profile piece, which aired Tuesday, June 23 on PBS, revealed the dangers that many women, often from Spanish-speaking nations, are confronted with after arriving to the U.S. for better opportunities. Frontline reteamed with Univision, Reveal from The Center for Investigative Reporting, Investigative Reporting Program at UC Berkeley and KQED to shed a light on the sexual abuse that often takes place during the twilight hours at the banks and offices that many Americans frequent.

The women, some with families and some without, often choose to work night hours so they have the freedom to pick up their children from school, prepare dinner and have daytime hours to handle personal responsibilities. However, when they go to work at 10 p.m. or midnight to work their low-paying jobs, they're often sexually assaulted or raped by managers, building supervisors, security guards, managers and coworkers who lurk the halls of the deserted malls, shopping outlets or hotels, waiting to violate those women.

According to the documentary, many women fail to report assaults because they fear job loss or repercussions, or because they can't communicate in English. Nonetheless, those who are able to verbalize the abuse they've endured are subjected to questioning and management fails to act in their best interest.

The first part of the documentary took a look at ABM industry, the nation's largest janitorial employer, which offers building maintenance and facility service. The firm was sued by 21 women who alleged that ABM failed to protect them from sexual harassment and assault by 14 of its male employees at the company.

Erika Morales was one of many women to detail the abuse she endured while working for ABM Industries Inc., suffering molestation by her supervisor. Frequently, he called her "delicious," and touched her breasts though she pleaded for him to stop. When she brought the assault to attention of another supervisor, she found that he was her cousin. The violation continued until she was forced to quit. She later found out the company's officials recognized that her supervisor was a predator, and he had previously assaulted another female janitor.

It took another year for them to learn that he was actually a convicted rapist, who'd been sentenced to prison for eight years. While he was employed at a small Bakersfield movie theater, he'd raped his boss' 18-year-old daughter in home. While Erika Morales never went to the police after she was assaulted, she later became the lead plaintiff in a class-action lawsuit against the company she worked for.

ABM, which cleans high-rises, airports, universities and government buildings across the country, is among 15 American corporations to be repeatedly targeted by the federal government for allegations of sexual harassment. Within the past decade, female janitors filed 42 lawsuits against ABM with the charges related to sexual harassment, assault and rape, and many of the lawsuits were ignored.

"In some cases, we've been made aware of inappropriate behavior and taken action. In other cases, allegations of wrongdoing have proven to be false and even malicious, often by individuals previously in consensual relationships that ended," claimed ABN lawyer, Miranda Tolar said in a statement. "Sometimes, there are other motivations."

"Rape on the Night Shift" is a follow-up to "Rape In The Fields" ("Violacion de un Sueno"). The second part of the documentary will examine what the government is doing to stop female janitors from getting raped. Also, the third part will showcase former janitors who've experienced cover-ups.