That looks an awful lot like a dangerous generalization.
I don't live in the US and I've never met a US police officer. Also, I do not support or defend police brutality in any way, it is crime and should be treated as such, however looking at the numbers of police officers in the US (around 1.1 million personal allowed to conduct arrests) you'd think that if they were ALL "scum" as you put it that you'd have a significantly higher rate of incidences of police brutality and deaths in police custody.
According to the ARD (Arrest-Related Deaths) Bureau of Justice stats; between 2003 and 2009 police in the US killed a total of 2,931 people they were attempting to arrest, of which 75% were being arrested for violent crimes. This sounds like a big number (about 419 people per year), but if viewed in terms of the number of violent crimes committed in the US (116,440,350,000 in 2013 for instance, taken from the FBI violent crime statistics of 367.9 violent crimes per 100,000 inhabitants in 2013) you realise just how tiny a drop in the ocean this number is.
More people die in traffic accidents over the Easter weekend DRIVING to the coast in South Africa between Johannesburg and Durban than are killed by the cops in the US in a year
Incidentally, around 143 US police are killed each year in the line of duty. Considering 13,286 people were killed in the US by firearms in 2015, according to the Gun Violence Archive, and 26,819 people were injured. I think it's a safe assumption that being a cop in the US is a dangerous job that brings you into contact with a violent criminals. Clearly violent criminals exist, they shoot at each other, the public in general and the police, some of them are going to be stupid enough to try to shoot their way out of an arrest and get shot in return. Clearly not all of the people killed by the police fall into this category, but I don't think we should judge ALL police on the fact that a tiny minority of their 1.1 million staff are brutal, but we should judge them instead on how they deal with those individuals and what they do to weed them out of their ranks.
So while the media may tell millions of us every day about how savage the police are in order to get us to buy their papers and tune-in to their news programs, I don't believe the hype is proportional to the size or nature of the problem. But hey, even-handed and rational news never sold any news papers or advertising spots, so I guess the chances of us ever seeing it are really slim.
Incidentally, how many cops have you had interactions with and why are they scum in your opinion?