Home videos that were taken decades ago, showing a young father playing with his children, help fill in the blanks for 30-year-old Kim Ellis.

"I have one memory," Ellis says. "And that's just him leaving for work, and he would call me boo boo. So he'd say 'bye boo boo!'"

It wasn't long after the home videos were taken that Kim would see her father for the final time.

"To this day, I can hear my mom's cry. Her screaming," Ellis says.

Her father, Dallas Police Officer Sunny Lov, who was a survivor of the Cambodian genocide, was killed in the line of duty on Nov. 4, 1990. He was hit by a car on the old Central Expressway while he laid out flares for a traffic hazard up ahead. His body flew into oncoming traffic.

He was 39 years old.

"I remember with unbelievable clarity the moment I found out he was gone," says his training officer, former Dallas Police Senior Corporal Scott Towns.

"He willfully placed his life in danger to protect other citizens," Towns says.

For nearly 30 years, Lov's family has worked to move past the tragedy. But recently, daughter Kim Ellis says the wound was split back open when her mother received a letter.

"Dear Ms. Lov," Ellis reads out loud. "A recent audit of your file identified an overpayment of your monthly survivor benefit... the total amount of the overpayment is $47,813.31."

The letter from the Dallas Police and Fire Pension system says the organization discovered it had been overpaying Lov's widow, Ellis' mother, for the past six years. Per state law, the letter says, they're now having her repay them for three of those years, totaling about $25,000.

"It just came out of nowhere," Ellis says.

Ellis says her mom's checks immediately went from about $2,000 a month to $841 -- because of a mistake the pension system made. She asked for more time to pay it back, but they said the allotted five years was already a compromise.

The 57-year-old woman is now making drastic lifestyle changes to account for this unexpected challenge. She was too shy to speak with us about it on camera, telling her daughter she just wants it all to go away.

"She's a good woman. She knows what's right, she knows what's wrong, she's not going to fight this. I feel like with me speaking out, I'm standing up for her. Because I don't feel like she deserves this," Ellis says.

So how did this happen? The executive director of the pension system Kelly Gottschalk says it was human error, discovered recently during a special audit of beneficiary accounts. They discovered another family was also overpaid, and one was underpaid.

Gottschalk told us they're charged with making sure the money in the fund goes to the right people. Gottschalk, who started in 2015, says she's sorry Officer Lov's widow is in this position.

They pointed out Mrs. Lov never alerted the pension system years ago when they say her payments erroneously increased. But Lov says she never noticed anything significant, and figured the pension system knew what it was doing.

Once she pays off the error, her monthly payments will bump up to around $1,265.

"It's difficult to imagine the pension expects retirees, widows and orphans to double check their math," Scott Towns says.

Towns, who has since retired and taken up teaching, says he's stunned by what the Lov family is now facing, after already having faced so much.

"Has she not paid enough? Has their family not paid enough?" he asks.

"It's not like he retired from Dallas or had a choice to leave," Ellis says of her father. "He gave his life up for this city and it just seems like this is the thanks that we get?"

And so for now, it won't be just family videos reminding them of Lov and his sacrifice; it will be the five years of repayments to the pension fund that will remind them, too.