Can I legally videotape police activity to bring before his superiors what I believe is harrment?

I have an officer who was suspended for his conduct. He was allowed a second chance so to speak. He has made it his mission to clean up the streets. AMEN! Problem his actions seem to be extreme. He is threatening people who are law-abiding citizens with accusations. He has it made up in his mind that certain individuals who he feels are responsible for his suspension are going to pay. What basically is considered police harment as opposed to enforciing the law? For instance is it justified if suspiscion arises based on his oppinion rather than facts, that he park his car on said persons property for hours on end only to speed off when noticed and return minutes later to repeat actions? Knowing that said officer with personal grudge is going to find something wrong regardless if there is OR isn't? This is happening to the point where innocent citizen is trapped in own home for fear of what he may be charged with if he leaves. Like a bully picking out defects of character on bookworm.