Connecdead by John Owens
Connecdead: Jake Lydon Mystery Series (Book 1)
Meet Jake Lydon -- a different kind of sleuth (and not in a good way.) The paunchy, long-haired, Hawaiian shirt-wearing, foul-mouthed, chain-smoking, near-alcoholic, semi-reclusive retiree has a different take on just about everything. Mostly he wants to do the one thing he's very good at -- Nothing.
But the mysterious death of a former boss changes everything. Helped by his homicide detective daughter, his laconic neighbour and drinking buddy, and a young computer hacking genius, Jake sets off on a wild quest to find the who, and why behind his ex-employer's murder.