When cops and a witness are murdered, a determined Homicide Detective must solve a space piracy case to find their killer and the controlling mastermind.

In response to the first one:

It is unclear why he must solve a space piracy case. On it’s on it implies no connection, and the logline offers no connective thread other than the same character is working both cases.
The potential hook of your story is the fact of the sci fi element. So embrace it. What about your sci fi setting gives this otherwise normal detective story unique? Use the sci fi setting to your advantage, make it necessary to the story. For example, in Minority Report the very thing Anderton is investigating is ingrained in the sci fi element of the story.