Police said the two brothers lived together in the apartment and got into an argument. Authorities said they believe the brother was involved in the killing of 31-year-old Phillip Pelayo.
The victim was rushed to the hospital but did not survive.
Edgar Pelayo is described as a Hispanic male, 6-foot and 250 pounds.
"We believe that Edgar fled the scene on foot," said Lt. Rober Binder of the Los Angeles Police Department. "We believe he's in the local area. We believe he has some friends and family he could be staying with."
