Police are investigating a fatal stabbing in Haverhill after a man with multiple stab wounds was found on a sidewalk on High Street on Wednesday evening. A spokeswoman for the Essex district attorney’s office said the 25-year-old victim was taken to the hospital, where he was pronounced dead. His name was not released. Police said a black Honda Accord with New Hampshire plates could be connected to the stabbing. The Eagle-Tribune reported that the car was recovered, but it was unclear whether there had been any arrests.