It's a painful reality that this murder has never been solved. That's something authorities hope to change.
HCSO homicide investigator Ruben Carrizal has created a massive file, cataloguing more than 300 names of possible suspects. He is the latest homicide investigator to take over the case. Past detectives on the case have retired.
He said, "This happened when I was in high school, but I'm going to be in this department for many years."
Allee was abducted as she walked to her Ford Aerostar van in the parking lot of Greenspoint Mall. It happened at about 7:30pm on a night in 1991. Allee's van was found burned about three miles away off TC Jester. Her body was found in another location, off River Laurel. She'd been shot at least three times in the head. Her service weapon and purse were missing.
At the time, deputies handed out fliers hoping to get information about the crime. They did. They have 20-year-old composite sketches of two men seen with Allee at Greenspoint Mall. Yet, despite witness statements describing these men, there have never been any arrests in the case.
Sgt. Dean Holtke with the Harris County Sheriff's Office said, "It's almost like someone punching you in the gut when you lose a fellow officer."
On Friday, authorities marked the 20-year anniversary with a call for help. Harris County Sheriff Adrian Garcia was a street cop with HPD back in 1991. He says the crime is as devastating to family and friends now as it was then.
"We want to solve this case," Sheriff Garcia said. "She is a member of our family and we want to bring closure to this case."
For investigator Carrizal, he follows up on every detail, making sure the file doesn't get lost or forgotten.
"I've actually had detectives that have retired that have called and asked how the case it going," he said. "I just keep working hard and hope I get what I need."
Anyone with information about the murder of Deputy Allee is asked to call Crime Stoppers at 713-222-TIPS (713-222-8477). Crime Stoppers of Houston will pay up to $10,000 for information leading to the arrest and charging of any felony suspect(s) in this case. All callers will remain anonymous.