His friends remembered how he loved to dance and how he could "light up a room with his smile."
His older sister remembered Fuller's love of food, video games and positive spirit.
"He was always loving, helpful," she said.
The church service was held at Cathedral of Worship in Littlerock, 37721 100th Street East.
The service followed coronavirus protocols, including sanctuary seating by invitation only. Everyone in attendance was asked to wear a mask and socially distance.
Autopsy complete in Palmdale hanging of Robert Fuller as family, friends continue to demand answers
A passerby found Fuller's body hanging from a tree in Poncitlan Square about 3:40 a.m. on June 10 and his death was initially ruled a suicide by Los Angeles County sheriff's detectives, although an official cause of death has not been made.
An attorney for Fuller's family says an independent autopsy is finished and they are waiting for results.
"The Sheriff's Department immediately declared his death a suicide without completing a full and thorough investigation,'' said attorney Jamon R. Hicks. "The lack of investigation and dismissal of this as a potential murder or hate crime has enraged Mr. Fuller's family and the entire Antelope Valley community.
"To rush to the conclusion that this was a suicide and not a homicide is extremely disturbing. Especially given the manner by which Mr. Fuller was found -- hanging from a tree,'' Hicks continued. "For African-Americans in America, hanging from a tree is a lynching. Why was this cavalierly dismissed as a suicide and not investigated as a murder?''
Hicks said the family is asking for the independent autopsy to be paid for by the city of Palmdale.
Los Angeles County Sheriff Alex Villanueva has vowed to conduct a thorough investigation into the death -- with cooperation from state and federal law enforcement.
Villanueva has said he called state Attorney General Xavier Becerra and reached out to the FBI, whose civil rights division will also monitor the investigation.
"It is in our interest to make sure that we leave no rock unturned,'' Villanueva said, promising full access to outside investigators. "This death investigation obviously is of great concern to the community, not only of Palmdale, but throughout the nation. Robert Fuller was a young man in the prime of his life, and his death obviously is painful for many people.''
A stream of the event is available on YouTube.