Authorities are filing charges against the driver they believe is responsible for the death of Jesse Johansmeyer last year in Hatfield.  Johansmeyer, of Florence, was struck by a pickup truck while attending a nighttime bonfire on March 24th.  The 19-year-old died the following morning at Baystate Medical Center.   The driver, who is not being named due to his age, is set to be arraigned in Hadley Juvenile Court on charges of negligent motor vehicle homicide and leaving he serene of an accident.