Los Angles County Sheriff's Lt. John Corina said authorities would like to talk to Wagner, star of TV's Hart to Hart and It Takes a Thief, since he was the last person to see Wood, his wife at the time of her death.
The sheriff's department reopened the investigation into Wood's death in 2011. She drowned Nov. 29, 1981, while on a boat off the coast of Santa Catalina, Calif. Investigators at the time believed her death was suspicious -- her body had bruises -- but ultimately ruled it as accidental.
Corina said that since reopening the investigation, more than 100 people came forward saying they had information about the case.
"As the investigation progressed, we've re-created the timeline, and [Wagner] was the last person on the boat with her," Corina said. "We're closer to understanding what happened."
The lieutenant said Wagner's story about Wood's death doesn't "add up to what we've found."
Capt. Christopher Berner said new information has led investigators to create a "more articulate timeline" of the events leading up to Wood's death.
Corina described the department's current efforts as the "last shot" to determine what led to Wood's drowning.