It's been 14 years since John Lin's daughter jenny was killed. She was just 14, and doing her homework in her Castro Valley home, when someone broke in and stabbed her to death.
The case remains a mystery.
"We still don't have enough evidence to bring the case to a closure at this point," said Lin.
Now, Jenny's face is emblazoned on a queen of hearts playing card, and so are the faces of 12 other murder victim's whose cases also remain unsolved.
Now the Alameda County Sheriff's Department is handing out those cards to the county's 4,400 jail inmates, hoping they'll be able to help.
"We're telling them, you want to play cards, you go play cards. Every time that you're playing cards, you're going to look at 13 cases of ours until perhaps one of them says okay, I'm going to come forward and tell you what I know about that case," said Sgt. Scott Dudek from Alameda County Sheriff's Department.
Inmates can take the decks with them when they transfer to other prisons -- that means prisoners around the state could see the faces of murder victims like Dana Ramm, who was found strangled to death on a Sunol road 22 years ago.
"Even if it's one case, it's all worth it," said the victim's mom Georgia Ramm.
Most inmates are aware there's reward money, or even a possibility of a reduced sentence in such high profile cases.
But Essley Green, who is serving 15 years for robbery in Dublin's Santa Rita Jail, says it's not worth it.
"If I see a guy on a card, me personally I wouldn't say anything. If that would get out, I wouldn't make that day, whatever that reduced sentence was," said Green.
John Lin hopes the cards he's holding in his hands provide at least some clues.
"Every day I get up in the morning, the first thing I think about is who did this to our daughter," said Lin.
The Alameda County Sheriff's Department hopes the playing cards will be as successful in California as they've been in Florida, where the project started.
So far, authorities in Florida have solved at least three cold cases thanks to inmates using the cards.