TPTK on the river

I thought the turn was an easy call, but I let myself time out on the river:
Full Tilt No-Limit Hold'em, $0.10 BB (7 handed) - Full-Tilt Converter Tool from FlopTurnRiver.com

Button ($14.55)
SB ($17.45)
BB ($10)
UTG ($10.40)
MP1 ($32.15)
Hero (MP2) ($10)
CO ($22.15)

Preflop: Hero is MP2 with K, A
1 fold, MP1 calls $0.10, Hero raises to $0.40, 4 folds, MP1 calls $0.30

Flop: ($0.95) K, 9, 4 (2 players)
MP1 checks, Hero bets $0.70, MP1 calls $0.70

Turn: ($2.35) 4 (2 players)
MP1 bets $2.35, Hero calls $2.35

River: ($7.05) Q (2 players)
MP1 bets $7.05, Hero folds

Total pot: $7.05 | Rake: $0.70

Why would he suddenly bet on the turn with KQ? Wouldn't he lead the flop or if he's not sure about his hand, wouldn't he check/call turn as well? I was planning on checking behind on the turn to induce a river bluff, but he donked on the turn

[tom]

stats? what kind of stuff is he limping?

the psb donk on the turn smells of a big hand though......

[Kbryce23]

A4 of diamonds LOL

A4 of diamonds LOL

Definitely part of his range, lol