Monk has trouble relating with Benjy because he never did any of the things most "normal" kids do when growing up. For instance, when Sharona told Monk to give Benjy some words of encouragement after losing a baseball game, Benjy had to show Monk how to hold the bat.
Nevertheless, Benjy comes to love Monk as a surrogate father. For one thing, he's constantly fascinated by Monk's brainpower, which he likes to show off and test in various ways - such as giving him the pieces to two jigsaw puzzles at once and timing how long it takes to solve them. On a deeper level, Monk gives Benjy the kind of trust and support that a son would normally receive from his father. One of their most significant experiences was when Benjy witnessed a murder while the trio were on vacation. Because the killers did an expert job of cleaning up, nothing appeared to have happened, and everyone, including Sharona, was inclined to write off the incident as an overactive imagination. Monk refused to disbelieve Benjy, and doggedly investigated the hotel grounds until he solved the case and proved Benjy right. As he said to Benjy during the case, "I don't have to be your father to believe you, or to be proud of you."
Despite his youth, Benjy develops a strong sense of morality and integrity that makes both Sharona and Monk proud. When Monk investigated magazine publisher Dexter Larsen, for murder, Larsen threatened to publish a set of racy photos that Sharona had had taken of herself when she was younger and struggling to make ends meet. Larsen expected that both Sharona and Monk would bow to the pressure rather than see Benjy be humiliated at school. But Sharona decided to ask Benjy what he thought, and Benjy assured her he could handle it, and told his mother and Monk not to let a "bad guy" off the hook just because of him.
On another occasion, he got into a serious fight at school trying to defend a smaller kid from bullies. His mother was initially mad at him, but later, after she was arrested for saving an innocent animal from being killed for a crime he didn't commit, she admitted that she was wrong and Benjy was right.
Benjy returned to New Jersey with his mother when she re-married Trevor Howe and moved out of California. They sent flowers after Monk's presumed death, and were planning to fly in to attend his funeral.
He is mentioned the last time in the Season 8 episode "Mr. Monk and Sharona," where Sharona states Benjy is now looking at colleges.
- Benjy was played by Kane Ritchotte in the pilot, "Mr. Monk and the Candidate," and in the entirety of Seasons Two and Three; Max Morrow played him in the remainder of the first season. This is because Ritchotte lives on the West Coast - the pilot was filmed in Vancouver, British Columbia, and the second and third seasons in Los Angeles - while Morrow lives on the east coast, and the remainder of the first season was filmed in Toronto.
- Julie Teeger, Natalie Teeger's daughter plays much the same role that Benjy did after Sharona left California - to wit, that of a surrogate child to Monk.
- In the non-canon novel "Mr. Monk and the Two Assistants" by Lee Goldberg, Benjy returns with Sharona to San Francisco when Trevor is jailed for murder. Sharona and Natalie, initially at odds with each other, gradually become friends, and Benjy and Julie bond, since they are roughly the same age, and share the same affection for Monk. Julie mentions to her mother that she doesn't want them to have something else in common: losing their fathers. It may be inferred that affection for Benjy is part of what moves Monk to investigate and clear Trevor's name (since another part of him would love to have Sharona back).