Deana, I laughed at your techie comments, we have all been there. But, really no problem. Anytime.
Lauren, if you feel an appeal to Curtis may help, please feel free to post on the site. If Curtis sees the site, he can always PM you, or I'm sure he probably has a way of finding your number, without you having to post it here. I think your intentions were good. Strange, but sometimes appeals strike a cord with people. You just never know.
Michelle, you mentioned the bottles from kids having a bush party. And, there being a tent. I hope the LE have a chance to talk to the kids. You never know if the tent had some overnight guests, that just may have seen or heard of something that morning that just may lead to somewhere.
I have to say, you all should be proud of your efforts. You've covered some really important bases right away. That is important because sometimes later you just don't have the opportunity.
Is there some way that the TTC may be able to hand over to LE the incoming and outgoing phone numbers Curtis had on his work phone. Where I work we have a record of these which may help them with some leads. Also, if Curtis has a cell with texting capability, I hope the LE have ordered the text messages for review. Probably is not a bad idea to have your home phone, text and email also reviewed. A small detail, hurtful feelings, signs of depression, a threat, extremely sad news, new friend, etc... maybe, just maybe a clue.
The leash missing bothers me. Were area trash cans looked into? I apologize for asking this next question, but if there were any signs of depression, or if the medication may have made him depressed, look in areas that the leash may have caused harm, either by him or another. I so apologize for saying that. (I have learned to look at all angles, not just the ones I find acceptable...but then again that may not be everyone's philosophy. No intentions of causing you harm, though.) My thought is that maybe somehow he got tangled up in it and just needs some help. Of, if the leash can be found, it may be a clue to location, and DNA. Thinking positive here.
Perhaps you can post a picture of the leash, and a description. That way people can look for it before it gets thrown away, moved, or recycled.