Mild PTSD- not military related.

Recently a close family friend of mine was killed. A man hid in my friends home and killed him whenever he entered. The man hiding ended up being one of America's most wanted criminals. He had been running since 2012. This has obviously had a huge emotional impact on my life and I feel like I may be developing PTSD from these events. I'd like to hear insight from others diagnosed and learn the symptoms and triggers.