Most Muslims from my experience do acknowledge other Muslims do commit sins like rape, murder, mass killings of civilians, theft, robbery, fraud and so on . For example, most Muslims acknowledge we have corrupt Muslim leaders, that Muslim armies have committed atrocities (like the Pakistani military killing Bangladeshis), Egyptian security forces using torture against civilians, some Muslims target civilians to achieve a political goal and so on. Some Muslims also acknowledge problems such as mistreatment of women, Jews, Christians, other minorities and so on.
However, even since 9/11 and the Iraq war, some Muslims have began to doubt information coming from the government. They've told us incorrect information before, so it is likely they will do it again. At times, there have been inconsistencies with the government's version of events. These incidents where innocent civilians get killed do occur at a time that is politically or financially convenient for certain groups of people. So it does cast doubt on information the mainstream media presents which comes from the government.
I'll admit, some Muslims are too quick to accept information that makes non-Muslims look bad from the mainstream media. For example, a soldier has killed some Afghan civilians. They are quick to accept this from the mainstream media and are less likely to question it, than compared to a Muslim soldier killing Afghan civilians.
What we need is a consistent approach to examining these issues. I always assume a person is innocent until proven guilty. If the person dies prior to a fair trial, then examining the information available, I tend to make a logical guess about whether the person has committed a crime, but I'm not certain.
In this case, I'd say it is very likely he killed innocent civilians and I'm awaiting for more information to be released. At one point, after the issue has died completely, I will assume that the person has committed the crime.
So let's try to avoid getting aggressive when having a discussion. Take a chill pill, even though I acknowledge this is a sensitive topic.