I'm not going to accuse anyone, just wanted to report this.
I think the key scene is in episode 02 from season 6. That person feeding pigeons..looks suspicious indeed. Patrick looks at him/her for a while, and he stops Lisbon from leaving him, just like he planned something. They start to talk about RJ and that one thing RJ didn't know. But at the end of their conversation, at 1:26 of the video, Patrick clearly looks again at that person. It lasts less than a second, but you can see it. Now, who is that person? It looks creepy, but he/she has a ring (If I remember correctly, RJ has a ring) and a watch, which looks suspiciously similar to Partridge's (you can see it in episode 01 from season 6).
If Partridge is dead, why would RJ send that person with Partridge's watch? 
I have no idea what this scene means, but I think it will make sense after episode 8.