Slayers (1999)

William Clay Decker is the town legend - a pseudo-vampire who sold his soul to live forever who is released in the early 1960s. Officer Belak is sent to investigate the vampiric murders, despite Mayor Decree's declaration the bodies had not been drained, and soon becomes a vampire. Will becomes enamored of a young woman, Lisa Strider, who has recently lost her mother, whom he rescues from attempted rape, and she carried his child, which she refuses to abort despite her doctor's wishes. The Dark Angel that supervises his vampiric choices kills Lisa's best friend, Ann Lowen, and make Will think he is her, while she marries her ex-boyfriend, on the condition that the children have her name, to help raise their baby, she thinking Will is dead. Thirty years later, they are killed by vampires, sending their children, Troy and Tracy Strider, after killing the vampires after the fact,in search of their half-brother, Jason, Will's son, a powerful vampire slayer, whom they learn from. By now, Lisa's hometown has so many vampires that the police work for them, and has its own resident vampire slayer, wisecracking Johnny DuPree, who team up with the Striders, while Will struggles with his own morals.