FBI detective Puzzle

[AppleyNO]

Old Mr.Rakesh was found dead in his bedroom by young Manish.
Manish recounted his dismal discovery to Detective FBI detecive Donald, who happens to be around the scene.

'I was walking by Mr. Rakesh's house when I thought I would just pop in for a visit. I noticed his bedroom light was on and I decided to peek in from the outside to see if he was in there. There was frost on the window, so I had to wipe it away to see inside. That is when I saw his body. So I kicked in the front door to confirm my suspicions of foul play. I called the police immediately afterward.'

With clue from Detective FBI detecive Donald, the police officer immediately arrested Manish for the murder of Mr. Rakesh. How did he know Manish was lying?

[Yayap]

Windows only frost up from the inside. Not outside.

[AppleyNO]

Windows only frost up from the inside. Not outside.

Well, at least you aren't Glip, the puzzle killer.

Good job

[Fatalis]

Windows only frost up from the inside. Not outside.

You learn something new everyday

[Nick]

You learn something new everyday

Frozen water vapor.

[Phyr]

Maybe the window was dirty, it rained and then shock freezed? What about dew that got freezed?