'No; he has a latchkey, and he let himself in.'

'实在不知道。有把弹簧锁钥匙，自己会开门进来。'

There was a spring lock on the door.

门上有把弹簧锁。

That latch is a bit stubborn, but I'll take care of it.

那道弹簧锁很难处理 但我会处理。

It was close upon twelve before I heard the sharp sound of his latchkey.

将近十二点钟，我才听到尔摩斯用钥匙打开大门上弹簧锁声音。

Pressing here and there, it only took him a moment to discover a latch inside the back.

到处按了按，很快就发现后面有个弹簧锁。

But according to Sam, there's like this swing bar lock, like a door latch secured from the inside.

但据萨姆所述，门上装有个类似门闩弹簧锁，从内部将门反锁。