You are right in the middle of a bunch of experts. Ask them. Being where you are, you must be involved with the study of photojournalism, so you really need to know this kind of stuff.
The basic rule is that if it was in the public view, or if it is on private property, but there is no reasonable expectation of privacy, then you can shoot it and publish it and sell it. You can also shoot on private property that is open to the public (such as a private park or mall), as the courts have held that the owners of the property have no reasonable expectation of privacy there. (This is less cut and dried than the public view, so check your facts well before waltzing into a public-private space and shooting.) You can also shoot on private property until you are asked to stop (including by posted rules banning photography). You can also shoot onto private property from public property, provided that you do not capture anything beyond what is in the public view. This means that you do not capture anything significantly beyond what the naked eye could see at street level from public property. What you cannot do is breach someone's reasonable expectation of privacy, for instance, by standing on a ladder to shoot over a high fence, and/or using super telephoto lenses to get close-up shots onto their property. The fence, and their distance from public property gives them a certain reasonable expectation of privacy that the law says cannot be disrespected.
In addition to these basic rules, the press is also granted a bit of leway in breaking news situations. For instance, a member of the press, in the performance of his or her duties, can shoot and publish photos taken on private property, if the events being shot are of public concern. For instance, a press photographer can walk into a burned-out shell of a house and take pictures of a family's burned personal items in order to tell the story of the fire. Likewise, the same photographer can take and publish photos of a police assault inside a private residence. Both of these are actual situations that have been allowed by the courts in legal challenges, and these or examples like them will be in any decent photojournalism textbook.
