SOUTH PHILADELPHIA (WPVI) -- It's been nearly four years since Michael Fox was taken from his family.
"We haven't learned anything new on the case," said Diane Fox, mother.
His mother, Diane, says not knowing what happened has turned her grief into anger.
"Your emotions go all over the place," said Fox. "You become angry now because you want answers."
Around midnight on June 22, 2012, police were called to a home on the 900 block of 8th street in South Philadelphia.
They found the body of 30-year-old Michael Fox in his third-floor bedroom, beaten to death.
Police say he'd been dead for two days.
"We're just hoping that when this airs it'll trigger someone's memory," said Fox. "We truly believe if not one person, more than one person knows exactly what happened."
The Citizens Crime Commission is administering a $1,000 reward and the City of Philadelphia is posting up to $20,000 for anyone with information that leads to the arrest and conviction of the person responsible.
Anonymous tips can be submitted by calling 215-546-TIPS.
Diane says they are coping.
"We do things to keep his memory alive. We have a scholarship, we did a buddy bench, we walk around the city on his birthday and put posters up," said Fox. "He's missed. He's greatly missed."
Crime Fighters: $21,000 offered in beating death of Michael Fox