Kindred Spirits. The Spirits Series, #2

Ghosts don't scare Chris Wilson. Murderers do. When a haunting investigation turns into a cold case revival, Chris is thrust into the most dangerous work of her career. Jimmy Brandt, a teenage ghost trapped in his brother's house, wants one thing: the truth. He was killed, and his murderer walked away clean. Chris and her ghost sister, Ron, agree to help him-whether Jimmy's brother is ready or not.
Derek Brandt built a career tearing apart the paranormal, not partnering with it. But when objects fly through his kitchen and his dead brother starts communicating through a medium he once publicly mocked, Derek has no choice but to face the impossible. and confront a past he's tried for years to escape. As Chris and Derek reluctantly join forces, their investigation uncovers buried evidence, dangerous leads, and a connection between them neither expected.
But their search also triggers something they didn't foresee:The person who killed Jimmy has noticed. Now a medium, her ghostly sister, and a hardened skeptic must solve a murder with a killer who's still at large-and watching their every move. Some hauntings start with unfinished business. This one ends with a fight for the living.