What does 張ってた (hatteta) mean in this context?

Question

Context: a detective is talking with the police who is the real culprit behind the recent crime. This police threw away his disguise costume to erase evidence, but it has been found by the detective.

Ｐ：この衣装は、どちらで見つけたんですか
Ｄ：そこのゴミ箱に捨てられてるのを、あの夜にすぐに見つけたよ。
　　あんなものを持って移動するのは危険だからね。
　　手近なところに捨てるだろうとは思ってた。
　　あるいは回収に来るかと思って張ってたけど、
　　流石にそんなリスクは負わなかったみたいだね。

My take: "I have observed (the trash bin where the police threw away the evidence) and thought that maybe you will come back to collect it (the evidence)."

Is my interpretation correct? Or, what should be a more proper translation?

Answer 1

I think it means definition 22 from デジタル大辞泉.

22 見張りを置く。見張る。「国道を―・る」

So the detective stood watch over the area to see if the culprit would return. This is because the detective thought it was possible for the culprit to return to collect the costume in the garbage can (回収に来るかと思って). However, he then laments that it seems that the culprit did not take that risk (流石にそんなリスクは負わなかったみたいだね).