Sometime prior to the 1990s, Hernandez became affiliated with organized crime in his native country of Mexico. He had visibly ceased to be a young man by 1991, suggesting he was born somewhere around the 1950's.
NCIS Season 3
Gibbs' wife, Shannon witnessed the shooting of a Marine in Oceanside & was going to testify against Hernandez in court & a federal agent was assigned to protect Shannon & her daughter Kelly. Hernandez fatally shot NIS Special Agent Kurt Mitchell in the head at long distance while he was driving Shannon & Kelly to their safe house, Mitchell died instantly, but Shannon & Kelly were killed in the crash. Hernandez then returned to Mexico & according to official NCIS files on the case, was never caught. This all happened while Gibbs was fighting in Desert Storm. NCIS Director Jennifer Shepard & Dr. Donald Mallard are the first ones to find out about Gibbs's secret.
NCIS Season 7
Forensic Scientist Abigail Sciuto & NCIS Special Agent Timothy McGee head to Mexico to teach a class about the forensics on cold cases. They use the horrific 20-year prior murder of a (traficante de drogos), a drug dealer named Pedro Hernandez- he left a cafe, he got in his vehicle to go home & he was gunned down at point-blank range in a "gang-style" shooting. His vehicle was abandoned soon after the incident. The police report however, is wrong, meaning that he was NOT shot at point-blank range. Abby receives a .338 Lapur MAG bullet (which Gibbs had mistakenly left behind after killing Hernandez) from Paloma Reynosa (who is Pedro Hernandez's daughter; which was unknown to them at the time). Shen then logs in to a computer & finds out that Hernandez killed Shannon & Kelly Gibbs (L.J. Gibbs's family) much to her surprise. As soon as Ducky & James Palmer received Pedro Hernandez's 20-year-old corpse, they begin the autopsy & they find the bullet that ricocheted inside of his skull.
NCIS season 8
NCIS Season 9
Hernandez's hallucination appears in Life Before His Eyes (episode), as both Gibbs & Former NIS Special Agent Michael Franks discuss what would've happened if Gibbs didn't kill Hernandez in revenge. Gibbs would've become a dirty alcoholic who pushes everybody away who attempts to reach out to him.
NCIS Season 13
Pedro Hernandez gets criminal Benson Long involved in the Drug Cartel & at the end of Personal Day (episode), Long taunts DEA Agent Luis "Mitch" Mitchell by saying "Daddy took a headshot.", referring to Kurt Mitchell getting shot in the head by Hernandez. As he walks away, Mitch holds him at gunpoint, presumably wanting to get revenge on him. Gibbs talks him out of it by stating that killing Hernandez didn't Shannon & Kelly back & that killing Long in revenge won't bring Mitch's father back. NCIS Special Agents Anthony DiNozzo Junior & Timothy McGee arrive shortly after to arrest Long.
NCIS Season 16
After 30 years of keeping this secret from the closest people to him, Gibbs reveals to McGee, Eleanor Bishop & Nicholas Torres that "he killed the man who killed his family. Judge Miles Deakin finds out about it & uses it against Gibbs to hopefully get him arrested, but this plan backfires & gets him arrested for hiring Mallory Madden to shoots Gibbs, but this fails as well.
NCIS Season 19
Hernandez appears in a flashback in Road to Nowhere (episode).
- Thursday February 14, 1991: Sergeant Tanner - (shot to death).
- Monday February 25, 1991: The car shooting (three fatalities):