[SH] NL50 KTs

Prima, $0.25/$0.50 No Limit Hold'em Cash, 6 Players

UTG: $50.75 (101.5 bb)
MP: $15.97 (31.9 bb)
CO: $62.21 (124.4 bb)
BTN: $48 (96 bb)
SB: $56.91 (113.8 bb)
Hero (BB): $67.47 (134.9 bb)

Preflop: Hero is BB with T K
2 folds, CO raises to $1.50, 2 folds, Hero raises to $5.50, CO calls $4

Flop: ($11.25) T 8 J (2 players)
Hero checks, CO bets $4, Hero calls $4

Turn: ($19.25) 5 (2 players)
Hero checks, CO bets $8, Hero calls $8

River: ($35.25) 6 (2 players)
Hero checks, CO bets $17.50, Hero calls $17.50

Anon table.

CO played 27/23 after 90 hands. I had quite an aggro image on the table, did some 3betting before.
What is he vbetting here? JJ/88/AJ/KJ(?)/JTs/Q9s are possible, but JTs/KJ are also quite blocked.