Peter Dunstan Crenshaw is a member of the "Three Investigators". He is the second investigator and is in charge of all physical matters, such as chasing, overpowering, and restraining suspects and criminals. He often gets hurt due to his job.
Peter has reddish-brown hair and is agile, fit, and well-built. In Toxic Water, however, he has light blond hair, which seems to be an error on the author's part. Since he does a lot of sports, he is the strongest and tallest member. His skin is tanned from surfing and diving. Depending on the novel, Peter's eyes are either described as brown or bright green, the latter being much more common. Peter has a prominent nose and elegantly curved eyebrows. Peter has a long scar on his right arm. In the novel, he gets it when an elevator he's in crashes, while it's from breaking open a steel door in the audiobook. Peter is generally considered handsome and looks like someone who could appear as a model in a surf magazine.
Despite being the strongest member, he's also the timidest one. He's usually the first one to suggest abandoning a case but ultimately always sticks around until the end. Peter himself insists that he's not timid, only cautious. But when it comes down to it, he doesn't shy away from putting himself in danger. His quick thinking saves the Three Investigators from drowning in The Mystery of the Dead Man's Riddle and in The Mystery of the Vanishing Treasure, he climbs up a 25 meters high wall with just a thin nylon rope to save Jupiter.
Peter is usually portrayed as the most simple-minded one. He often has trouble understanding Jupiter due to his use of difficult words and heavily relies on Bob to "translate" them for him. Whenever Jupiter solves a case, he needs somebody else to further elaborate on Jupiter's explanation. Since Ghost Bay, he carries around a "vocabulary book" in which he writes down the unusual words Jupiter uses and their meaning. Peter is also the only member who believes in ghosts and magic.
Although he's usually kind and caring, he sometimes expresses the desire to take revenge on those who have wronged him.
Peter and Jupiter often get into fights, usually because of Jupiter's way of speaking. They have their worst fight in Classified: UFO. Nonetheless, when Jupiter has to choose who is his best friend – Bob or Peter – in Message from the Underworld, he ultimately chooses Peter because he is thankful to Peter for saving his life multiple times.
Peter seems to get along much better with Bob than he does Jupiter. On multiple occasions, Bob and Peter go out by themselves, leaving Jupiter out of it.
Since Peter's girlfriend, Kelly, was eventually cut out of the audiobooks, a lot of the scenes that originally featured her were replaced with Bob. This lead to many scenes gaining a strong homoerotic subtext. In The Missing Pilot, for example, Bob and Peter kiss after Peter solves a riddle.[note 1]
Kelly is Peter's girlfriend. They share an interest in animals and sports and are the only couple to never break up. Peter is loyal to Kelly and always does what she tells him to. They do, however, get into fights a lot, mostly about Peter's activities with the Three Investigators. Kelly feels like Peter spends more time investigating cases than with her, while Peter tries to convey the importance of his work to her.
In the 2007 video game The Incas' Gold, Kelly and Peter are engaged but it is not known how canon this is since it's never brought up again in the novels or audiobooks.
Peter deeply hates Skinny.
- Athleticism: Peter is the most athletic and fit member. He actively practices a large variety of sports, including track and field, soccer, basketball, surfing, diving, and swimming. In Long Shot, he's even told that he has the potential to become the next basketball star player, and in Soccer Mania, he catches the eye of a professional trainer.
- Lockpicking: Peter owns a lock picking kit and is able to pick almost every lock.
- Sense of Direction: Peter has a keen, innate sense of direction and is always able to find the right way. In The Mystery of the Stuttering Parrot, it's even said that he's able to correctly navigate to places at night that Jupiter wouldn't even be able to find at daytime.
- Mechanic skills: Peter is seen fixing cars on several occasions. He later starts buying used cars, which he fixes at the Jones Salvage Yard and then sells for a profit. But despite his mechanical prowess, he's quite lost when it comes to computers.
- Talented poet: Despite hating poetry, Peter is especially gifted in the craft.
- Talented driver: Peter is an extraordinarily good driver. His driving skills even save the Three Investigators' lives on multiple occasions.
- Animal Care: Peter is experienced in taking care of animals, even wild ones, since he's worked on several nature documentaries with his father. In The Secret of the Crooked Cat, he even tames a lion.
- In the German version, his name was changed to "Peter Dunstan Shaw".
- He retains his original name in the audiobook series Die DR3I due to copyright issues.
- Peter is the oldest member of the Three Investigators.
- Peter's tonsils have been removed.
- Because of his often dangerous activities with the Three Investigators, Peter has already written his testament.
- Although many people assume that his question mark is the red one because it's the second one, it's actually the blue one.
- Peter is allergic to cats.
- He does not yet seem to have this allergy in The Mystery of the Whispering Mummy.
- In The Case of the Dancing Dinosaur, Peter becomes an honorary member of the wind tribe.
- Peter is a synesthete.
- Peter goes jogging four times a week for 30 minutes.
- Peter hates rats and insects.
- Peter is the first investigator to have his own car. He drives an old red MG.