FALL RIVER, Mass. — Aaron Hernandez once seemed to be a man with a bright future. At age 23 he had a Super Bowl appearance under his belt and a $40 million contract as a star tight end with the New England Patriots. He and his fiancee had started a family, living in a mansion in the Boston suburbs with their 8-month-old daughter. This week, prosecutors will paint a different picture of Hernandez: they will portray him as a killer who orchestrated the shooting of semiprofessional football player Odin Lloyd. Hernandez was arrested days after Lloyd’s bullet-riddled body was found in an industrial park near his North Attleborough mansion.