A young journalist must turn detective when he gets caught up in the fatal conspiracy behind the Jack the Ripper murders.

Hi, I'd say be more specific in your revised logline - we connect and care about the main characters you present. In this you have some potentially gripping but then the stakes are generic - more lives are lost - but we can't grasp this as a personal connection as we see news all day about public lives lost. I'd either say they're trying to kill him before he sorts it out like Three Days of the Condor. Also, I'm not sure if this is your story, but this looks like he's a journalist so his own organization is a newspaper, hence you're saying a newspaper is killing all the prostitutes? If so, I'm thinking this is a bit unlikely, but it might make a really compelling story, that's just my personal reaction to it.

I hope any/all/some of that helps.

Thanks for the feedback everyone - how's this?

When a young journalist discovers a conspiracy behind the Jack the Ripper murders in his own organization, he must expose it before more lives are threatened.

"...gets caught up in the fatal conspiracy..." is a vague description of an inciting incident. what exactly was it that got him caught up?

Did someone frame him? Is his life threatened somehow? etc...

Hope this helps.