Judaism is a monotheistic religion, with the Torah as its foundational text (part of the larger text known as the Tanakh or Hebrew Bible), and supplemental oral tradition represented by later texts such as the Mishnah and the Talmud. Judaism is considered by religious Jews to be the expression of the covenantal relationship God established with the Children of Israel. It also requires circumcision for male babies.
Judaism is also often considered to be an ethnicity, with many Jews feeling a strong cultural identity with being Jewish.
Dr. Charles Kroger is Jewish, as was the actor who plays him, the late Stanley Kamel. Ted Levine, the actor who plays Leland Stottlemeyer, was born to a Jewish father of Russian descent and a Welsh/Native American mother, though Stottlemeyer is not Jewish. In the streaker subplot for Mr. Monk and the Red-Headed Stranger, Lt. Randy Disher, while pursuing alongside Stottlemeyer a male streaker (later revealed to be Sharona Fleming's then-current boyfriend) who had disrupted an LAPD speech for the second time, commented, when questioned by the police dispatch about the suspect's religion, that the streaker "certainly ain't Jewish."