TAMPA — The night before he shot his wife and two teenagers in the head, Darrin Campbell insisted that the family gather for dinner and spend time together in their leased Avila mansion. His order for a family meal was so out of character that the wife and daughter told their friends.No one could have predicted the gunshots or the flaming horror that engulfed the home at 16223 Sierra De Avila the next morning. But for weeks before the May 7 murder-suicide, Campbell's loved ones had been noticing unusual behavior, according to investigative reports. The Hillsborough County Sheriff's Office released records Wednesday showing the agency has closed an investigation of the triple murder, suicide and arson — without determining why any of it happened."Based on my investigation and the information that I have at this time, I am unable to determine Darrin Campbell's motive," Detective Charles Keene wrote. The documents offer new insight into the dynamics of a doomed family and allow a more critical view of Campbell's final days, drawing from law enforcement interviews with friends, neighbors and school officials. Wife Kimberly, 51, son Colin, 18, and daughter Megan, 15, were found dead in a house that had become an inferno, fueled by gasoline and fireworks bought by Campbell. Investigators determined that he shot them, set the house on fire and killed himself. It shocked the community. Campbell, outwardly, appeared to be a family man who took an interest in his children's activities, even joining the board of Carrollwood Day School and working as treasurer. He showed up at his son's baseball games. Beneath the surface, some saw a man wired too tightly. School director Ryan Kelly called him hot-tempered and unreasonable. School baseball coach Nicholas Rodriguez said the father would scream at people one day and act the next as if everything were normal. Rodriguez wondered if Campbell was bipolar, one investigator wrote. Kimberly Campbell had said recently that her husband was "not the same man she married," one of Megan's friends reported.Megan told a friend her dad had been acting weird for several weeks. Multiple friends had heard her complain about him. He was "crazy," "really strict," too hard on her, she would say. She likened him to Hitler. Was it teenage exaggeration? How could anyone know?One friend noticed increasingly frequent bruises and questioned Megan's explanations that they came from dancing. She died with a large one on her arm."Megan said her dad gets bruises really easy too and told Megan it's a sign of intelligence," an investigator wrote.Colin was the one often seen arguing with his father, and it was usually about baseball, friends noted. The day of the killings, Colin was supposed to start a baseball camp at Hillsborough Community College. Rodriguez had helped him get accepted.Colin was an average baseball player, the coach reported, but his father seemed blind to any limitation, demanding that Rodriguez find him a scholarship to a Division I school. "Darrin Campbell appeared to him as living vicariously through his son's baseball career," the investigator wrote.Colin told a friend that he thought his family was spending more than his father earned. They paid $5,500 a month to rent the mansion. Campbell had recently started working at a digital records company. The Sheriff's Office examined his financial records looking for a motive, but reported no irregularities. The school also didn't find anything missing.Adult friends characterized Campbell as quirky, recalling a $250-a-plate charity dinner he attended with his wife in April. He got up to use the restroom before the main course was served and never came back to the table.Times staff writer Dan Sullivan and news researcher John Martin contributed to this report. Contact Patty Ryan at [email protected] or (813) 226-3382.