The man was shot in the hand shortly after 1 a.m. at the Red Line station at the intersection of Vermont Avenue and Sunset Boulevard, according to the Los Angeles Police Department. His condition was described as stable.
The identity of the suspected gunman in custody was not immediately disclosed. The weapon was recovered by investigators, the LAPD said.
RELATED: Rape suspect sought after brutal attack at East Hollywood subway station
The circumstances that led to the shooting were under investigation.
The incident occurred as the search continued for a man who strangled, punched and raped a 60-year-old woman at the same subway station on March 14.