He told his ex-fiance (Gen) in an email about the accident. He also professed his love for her and basically told her she was the love of his life. At this time Michelle was pregnant with their son, Rylan, and it was a few months or so before her murder. Gen had been married for some period of time herself and had not been in contact with JY for years. The email was sent to a school email address where Gen used to work but she didn't work there anymore. She didn't see the email until some time much later (perhaps as a result of the investigation and LE finding the email on JY's account).
Regarding the removal of rings, don't forget JY either swallowed or pretended to swallow his camp friend's wedding ring a couple weeks or so before MY's murder. The friend was in town for a conference and stayed at JY's house. MY was in NY on a trip. The friend & JY drank, got tipsy, and had sex. The friend was newly married. Then, when MY came home from her trip to NY, that's when JY did the wedding ring thing where he asked the friend to see her ring and he took it and wouldn't give it back (acted like he swallowed it). She had to wait until the next day for him to 'produce' the ring. She testified she was very upset at this. This is also the friend who JY drew the mustache on her face after she fell asleep (drunk, after they had sex).
He has a real issue with engagement/wedding rings. No wonder Michelle's wedding ring /diamond ring was also removed from her finger. Fits a pattern.