In the scene when Ted and his girlfriend Lee are celebrating with friends at a party, a woman walks up to Lee introducing herself as "Beverly" and talks to her about working with Ted at a crisis center. Her character is clearly a reference to Ann Rule, a true-crime author who met and worked with the real Ted Bundy at a crisis center in Seattle, Washington during the early 1970s. Furthermore, Rule did, in fact, meet and talk with the real Ted Bundy's girlfriend at a Christmas party one year. Rule would later write a book about Bundy and his murders.
The names of the victims in the cast of characters are fictional and not the names of the actual victims of Ted Bundy.
A scene where Ted Bundy takes one girl, fully conscious, into the woods, talks with her and then kills her befits the horror movie vibe this movie takes on Bundy. It's most likely, based on reports, evidence and Bundy's own confessions, his victims were unconscious when he strangled them (Bundy even bragged that he never "tortured" his victims). This is why Ted would leave nothing behind of himself to directly connected him to the murders i.e. there wouldn't be a struggle between him and his victim to leave parts of his skin in their nails, etc.
Photographs of the real Ted Bundy are featured in both the opening and closing credits of the film.