The shooting occurred at 12:43 p.m. Saturday at Crenshaw Boulevard and Slauson Avenue, Officer Rosario Cervantes of the Los Angeles Police Department told City News Service.
Paramedics took the man believed between 35 and 40 years of age to a hospital, where he died, LAPD Officer Drake Madison said.
The suspect was described by Madison as a man between the ages of 25 and 30.
The shooting occurred on the walkway near the Hyde Park K Line Station, according to LA Metro spokesman Dave Sotero.
The victim reportedly had an argument with a group of people, Sotero said.
"Metro extends its sympathies to the family of the victim," he said. "Metro Hyde Park Station is currently closed while the Los Angeles Police Department conducts its investigation. K Line trains are turning back at Leimert and Fairview Heights Stations until further notice."
The K Line is a 5.9-mile, north/south route between the Jefferson Park and Westchester neighborhoods.