Our Demons by Cameron Dawkins

Detective Superintendent Jack O’Connor knows that, between his family issues, his Borderline Personality Disorder, and his alcohol problem, he’s becoming a bit of a Columbo-esque character.
He has more than enough of his own demons to be battling without having to worry about catching a deranged serial killer, but, as the bodies start to pile up and with the people of Bristol at risk, it’ll take all of his unorthodox methods and scathing sarcasm, as well as a little help from an old, eccentric, motorbike-riding, cat-lady of a psychic, to stop this demonic murderer.