TNT’s latest “Dallas” episode, “Ewings Unite!,” offered a few potential clues in the “Who Killed J.R.?” mystery – but not many. Here’s what I think we know.

• J.R. was searching for Pam. At the end of “J.R.’s Masterpiece,” Bum (Kevin Page) told Bobby, John Ross and Christopher that J.R. had been looking for Christopher’s “mother” before his death. Since Bum didn’t specify which mother, I suggested J.R. wasn’t necessarily on the trail of Pam (Victoria Principal), the mom who adopted Christopher and later abandoned him and Bobby. My left-field theory: J.R. was hunting Christopher’s biological mom Kristin (Mary Crosby). Yes, I know she supposedly drowned in the Southfork swimming pool, but hey, this is “Dallas.”

In “Ewings Unite!,” we seem to receive confirmation that Pam was the target of J.R.’s search after all. This happens when Bobby (Patrick Duffy), while filling in the Ewing cousins on the history of Cliff’s company, holds a stack of papers and says, “This is a summary of the financial reports for Barnes Global, dating all the way back to its inception, when it was started by Cliff’s mother. Now she divided that company up between the three children: Pamela, Cliff and Katherine. Katherine’s dead. So if Pamela’s still alive, she could be a silent partner in Barnes Global. Maybe that’s why J.R. was looking for her – to help us take Cliff down.”

Christopher (Jesse Metcalfe) responds: “If my mother’s alive, I’ll find her. It’s about time I did.”

Bobby’s history lesson isn’t exactly how I remember the origin of the old Barnes/Wentworth empire, but setting that aside for a moment, this scene seems to offer two things: a) confirmation that J.R. was indeed trying to find his old nemesis Pam, and b) Bobby’s theory that J.R. wanted Pam to help him stop Cliff.

In other words: There’s no reason, at this point, to believe Kristin is anything but dead.

• The list of suspects is taking shape. In addition to Kristin, the list I posted last week of eight potential suspects included Katherine (Morgan Brittany), who I figured would want J.R. dead because she’s still holding a grudge against the Ewings. Now that we know Katherine is dead, she comes off the list too. (Presumably Katherine’s demise occurred sometime between the end of the original “Dallas” and the beginning of TNT’s revival.) Is it possible she’s still alive and Bobby doesn’t know it? Sure, but there’s no evidence to support that one either.

I also think we can drop the Ewings’ disgruntled lawyer, Mitch Lobell (Richard Dillard), from the list of suspects, since no one has mentioned him and he was a long shot to begin with. And even though I’m still suspicious of J.R.’s friend Carlos del Sol (Castulo Guerra) – who, we learn in “Ewings Unite!” is investigating Harris’s Mexican trucking operation on Bobby’s behalf – there’s no reason to consider him a suspect at this point either.

This leaves three chief suspects, beginning with Cliff (Ken Kercheval), who wouldn’t seem capable of killing J.R. – until now. In the chilling finale of “Ewings Unite!,” Cliff orders Harris’s henchman Roy Vickers (Alex Fernandez) to blow up the Ewing Energies methane extraction rig – even though Cliff knows the blast might harm his pregnant daughter Pamela (Julie Gonzalo). If Cliff is willing to risk his own flesh and blood, why wouldn’t he be willing to take out J.R.?

The second suspect: Harris (Mitch Pileggi), who joined forces with Cliff in “Ewings Unite!,” just like J.R. predicted in his note to John Ross (Josh Henderson). I still don’t know why Harris would have a beef with J.R., unless he believed getting rid of him would leave Bobby and Ann vulnerable to attack. I doubt the “Dallas” producers will have Harris turn out to be J.R.’s murderer, though, even if his altercation with mother Judith (Judith Light) at the end of “Ewings Unite!” suggests a violent streak.

The third and final suspect: J.R. Yes, I know: It’s unlikely Larry Hagman’s iconic character would arrange his own death, even if it turned out to be part of an elaborate scheme to set up Cliff, Harris or one of his other enemies. But I keep coming back to a point I made last week: Who else on “Dallas” is big enough to take down J.R. Ewing – except J.R. himself?

• There’s still a lot we don’t know. “Ewings Unite!” opens with the reading of J.R.’s will, in which John Ross somehow inherits half of Southfork from Miss Ellie and John Ross and Sue Ellen (Linda Gray) split J.R.’s share of the ranch’s lucrative mineral rights. You might think an inheritance this huge would make John Ross or Sue Ellen suspects in J.R.s death, but c’mon, that would be nuts. The new “Dallas” producers wouldn’t go that far, would they?

“Ewings Unite!” doesn’t shed much light on the other clues in the “Who Killed J.R.?” mystery. In addition to the discovery that J.R. was searching for Pam, “J.R.’s Masterpiece” also ended with Bobby receiving a mysterious document from his deceased brother. In “Ewings Unite!,” John Ross refers to the document as “a letter,” but Bobby declares he won’t reveal its contents until J.R.’s master plan is implemented. “Because that’s the way he wanted it,” Bobby says.

We also still don’t know what to make of the gun that J.R. left for John Ross. While watching “Ewings Unite!,” it occurred to me: Could this be the gun that Kristin used to shoot J.R. all those years ago? If so, might it signal her eventual return? Uh oh, here I go again!

Who done it? Share your theories below and read more posts on Dallas Decoder’s “Who Killed J.R.?” page.