Silvio is the youngest of three brothers, descended from rural Italian aristocrats, and grew up in his family's ancestral home Villa Caruso on the Amalfi Coast. When he was a child, his father died and his twin older brothers ran away from home, never to be seen again. He subsequently lived alone in Villa Caruso with his mother, academic Isabella Caruso, and she psychologically abused him to make him increasingly dependent on her. He is very nervous and introverted by nature, especially towards women, which the ICA diagnoses as gynophobia.
In high school, Silvio miraculously began a relationship with a popular girl named Amelia. However, Silvio's mother paid their gardener's son to seduce her and showed Silvio photographic evidence of it on their prom night. She then told him "Romantic love is fleeting. Only a mother's love endures".
Exactly two years before Silvio was assassinated, his mother died in her sleep from seemingly natural causes.
Diana Burnwood mentions in the World of Tomorrow briefing that Silvio is a former client of the ICA. It's later revealed that Silvio's requested hit was on businessman-turned-politician Marco Abiatti, which 47 accomplished in the mission Landslide.
Prior to his work with Ether Corporation, Silvio established a reputation as one of the world's top stem cell researchers. Shortly after his mother passed away, Ether hired him to develop an extremely deadly and controversial bio-weapon. The weapon was a contagious virus that responded to a target's DNA, and would lay dormant, unnoticed and harmless among the general population before reaching its target and killing them. Diana described it as a tool for potential "armchair assassins", and "a serious threat to our craft and trade". Inspired by his own troubled upbringing and insecurities, Silvio wanted the virus made available to practically anyone whereas Ether wanted to reserve it for use only by world leaders. Ether's upper management kept major shareholders in the dark about the virus, and one of the major shareholders - an unnamed woman with moral objections to the virus - was supposedly the one to call a hit on Caruso.
- Caruso hired a world-famous chef to try to replicate his mother's signature spaghetti, to no avail. A search in the kitchen's storage room reveals that she simply used store-bought cans of spaghetti, even if these are virtually non-existent in Italy.
- One of the guards in the underground lab can be overheard claiming that Caruso has Asperger's Syndrome (characterized by high intelligence and socially awkward mannerisms among other traits).
- If Agent 47 impersonates Dr. Oscar Lafayette and lets Silvio's therapy session progress long enough, Silvio will reveal he was the one who caused his mother's death by smothering her with a pillow. Ironically, 47 can then kill Silvio with the same technique on the two-year anniversary of his mother's death.
- Silvio, despite his gynophobia, is planning on conquering his fear, marrying, procreating and having a child to continue his bloodline. Unfortunately, he was killed a virgin.
- His watch is stopped at 11:00:33.
- His name is misspelled as "Silvo Caruso", instead of Silvio Caruso in the ICA target profile introduction screen.
- His mother can be found in the Freeform Training, where you assassinate Kalvin Ritter.
- He has hired the detective Sal Falcone to collect the DNA samples of all the people who had bullied him at school. It is heavily implied that he intended to have them all killed by the virus.
- He seems to distrust De Santis, and keeps a sample of her DNA in a safe up in the attic.
- By using the Memory Lane challenge method to assassinate him, 47 will use a videotape of Silvio's childhood to distract him. The reel contains photos of his youth while a song is played. The lyrics have the lines "forty seven ways to make you pay", probably as an Easter egg referencing the game's main character.
- His age is listed as 41 according to the psychological assessment found in his mother's room. The assessment was made in 2016, which would make him around 44 during the time the mission is set.
- Silvio has a plane that he can use to escape, making him one of the only targets in the game to be able to do so. This plane can be shot down by 47.
- If 47 holds Silvio at gunpoint, he will start to break down and cry, claiming that he is being bullied again, just like how Abiatti bullied him in his childhood (by throwing him in a well). He then begs for his life, stating he is still a virgin and asks 47 for mercy.