Hundreds of people, including city leaders, attended the services at Our Mother of Good Counsel Church, located at 2060 N. Vermont Avenue.
Joseph Gatto, 78, was found murdered in his Silver Lake home on November 13.
Police want to speak to a particular suspect who reportedly pulled a gun on neighbors just one day before Gatto's murder.
The suspect was described as a white male in his 20s. He carried a tan backpack and was wearing a multi-colored, hooded sweater and tan pants.
Anyone with information related to the case was asked to called detectives at (800) LAPD-24-7.