Spider-Man P.I. is a side mission in Marvel's Spider-Man. Spider-Man finds a woman named Carmen, who is concerned because her husband Rodrigo is acting weird and meeting a woman who she suspects is involved with organized crime. She knows he is meeting with a woman at the Detox center.
After arriving at the Detox center, find a good hidden location, preferably a perch atop a lamppost with a view of her face, and take the woman's picture. After this, she leaves in a vehicle and meets up with another person. Follow her and web to the ceiling above him to take his picture as well, then follow him as he takes the subway. The mysterious woman gives him the plans and Spider-Man sends his picture to Carmen who identifies him as Deshaun, a former friend of Rodrigo's from college who later went to prison on robbery charges.
The man will exit the subway and enter an office building. Climb up the outside of the building and spy on him and the man he meets. Take photos of the whiteboard and the screen for evidence, using windows that provide a clear view of each. After this, the two men leave the building and get into a vehicle. Follow it and a second vehicle.
Both vehicles will need to be stopped, and the easiest way to do this is by stopping the leading vehicle first. The second car will stop behind it and the driver can be easily defeated. Spider-Man will relay the information to Carmen, ending the mission.
Behind the scenes
When the men are meeting inside the building, one of them, Niko, reassures Dashawn that they can trust Roman, the getaway driver, pointing out that he is his "brother's kid". This is a nod to the main characters of Grand Theft Auto IV: cousins Niko and Roman Bellic.