Video taping in NJ

Although I cannot give you specific legal advice, I can tell you that the kind of activities you described can sometimes lead to legal trouble. It sounds like the agency you're interviewing with is a private investigation business, in which case it would fall under New Jersey's Private Detective Act. In part, the act states that employers are accountable for their employees' good conduct in the course of business. However, this does not mean that you could not be held liable if you invade someone's privacy on the job. I recommend speaking to your prospective employer about your concerns of personal liability. 

In regard to the second part of your question, it's generally OK to record people without their consent in a public setting, such as a public street or park. This would also include photography of someone on private property if they are visible from public property, such as a sidewalk. Keep in mind, however, that you can't use special equipment to see through or around barriers.

But recording someone in a public place is not a surefire way to avoid a lawsuit -- photographing private activities that happen in a public place is usually not allowed. For example, if the wind causes a woman's skirt to blow up and expose her undergarments, it could be a violation of her privacy to photograph the scene -- even if it happens in public. Furthermore, it would probably be a violation of privacy to photograph people through a hole in their backyard fence without their consent. In New Jersey, it is unlawful to intrude upon one's privacy in a manner that would be "highly offensive to a reasonable person." See Hennessey v. Coastal Eagle Point Co., 609 A.2d 11 (N.J. 1992). Because most people expect to have a certain amount of privacy in a fenced-in private area and would be offended by someone photographing them in that setting, it would likely be unlawful to do so. Another example of such a privacy violation would be using a telephoto lens to photograph people through windows in their homes. 

In short, it's always safest from a legal standpoint to get consent from people before you record or photograph them and to avoid recording people on private property. For more information on privacy issues, see the Gathering Private Information section of the CMLP Legal Guide and the CMLP's Newsgathering and Privacy video on YouTube.