Regarding cutting, didn’t Eric’s autopsy show that he very well may have self-harmed/cut as well? I thought I remember reading that he had cuts on his upper left arm at the time of death

The reality is that Dylan said he cut and Eric didn’t mention anything about it. On the autopsy reports, it indicates some varieties of abrasions (not specifically described as “cuts”)  were found on both boys but it does not indicate precisely how they got those marks. We can speculate how those marks originated but we don’t know conclusively if they originated specifically from cutting per say. It seems likely but that is speculation and not a fact.

 We know Dylan did engage in cutting because he indicates he’s doing so while in the midst of writing an journal entry. He did so on at least one occasion if not a few others from time to time.

Some people believe Eric self-harmed based on the findings in the autopsy report and other people don’t assume the marks are specifically from cutting.. There is no way to really verify it. You can read the autopsy files and decide for yourself based on the type of marks found present and noted by the coroner.