Along with talks that Tony DiNozzo might have a sister, his father has also returned in "NCIS" episode 13 season 19.

"NCIS" season 13 episode 19 is entitled "Reasonable Doubts." According to Design and Trend, episode 19 saw the return of Robert Wagner as Anthony DiNozzo Sr., Tony's father. As per the publication, the return of Wagner's character is probably a way to set up the path leading to Michael Weatherly's exit from the crime procedural television series.

According to Spoilers Guide, episode 19 saw the NCIS team determine the liar between the wife and the mistress, following the death of a Navy journalist. Also, Anthony is set to help a homeless woman, who claims that he is her father. At this point, it is assumed that fans would think that Tony might have a sister in the form of this homeless woman.

In a promo video, the team members discuss as to whether the true killer was the victim's wife or his mistress. Dr. Mallard says "scorned wife or jilted lover?" while Gibbs remarks that they had varied opinions.

"NCIS" showrunner Gary Glasberg also shared his thoughts on whether fans will see a younger Gibbs in the current season. In his interview with TV Line, Glasberg revealed that seeing Gibbs' past was on the back-burner at the moment. It was also revealed that the remaining "NCIS" episodes will lead to Weatherly's exit, with episode 21 marking the arc of his departure.

"NCIS" season 13 episode 19, "Reasonable Doubts," aired on Mar. 22. It is followed by episode 20, "Charade," which airs on Apr. 5.

Watch the episode's promo video here.