Dartmoor Feast A privare Moment bug?

I cant seem to take the picture ? i tried all possible angles, took about 50 pics , and challenge doesnt pop up

For this challenge you need:

Get Alexa to sit beside the dead body and talk to it.
To get this done you need to follow a Means, Motive and Opportunity mission story.
If I remember correctly you need to accuse Emma. But feel free to accuse the butler, I believe she walks to the corpse in this two cases. But she won’t go there if you blame a suicide.
When she’s there and talking just stand behind her (I believe at any spot), pull out a camera and go ahead

i did the whole investigation again, and niw i got it, tnx

I got it earlier without doing the mission story.