Investigators seek tips in dozens of unsolved murders, including Dr. Mark Hausknecht

HOUSTON, Texas (KTRK) -- Twelve days after Dr. Mark Hausknecht was gunned down in the Texas Medical Center, a suspect has been charged in his death.

As detectives work to find his alleged killer, there are other unsolved murders they're continuing to investigate, like the murder of Josue Flores.

Police: Houston doctor killed by man whose mother died during surgery

Flores was murdered walking home from school in May of 2016. It prompted neighbors to form a group called "Safe Walk Home." It's comprised of 150 volunteers who ensure kids get to and from school safely.

RELATED: Search for justice: A timeline of the Josue Flores murder case
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Here's a closer look at everything that has happened since Josue Flores' brutal murder in 2016.

"The streets are cleaner, more attention is being given to the students. There's a lot more reporting to the police officers," said Stella Mireles-Walters.

While the program is working, the search for Josue's killer continues.

Meanwhile, there's another unsolved murder out of Lake Houston. A woman's severed head was found in a bag in March. Investigators are still working to identify her. They have a sketch but detectives are going one step further. The Texas Rangers are working to create a 3D computer rendering of her.

RELATED: Volunteers find human head in trash bag in Lake Houston
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Volunteers find human head in trash bag in Lake Houston

Investigators have also worked with the Harris County Medical Examiner to get her DNA into a system that would identify the woman, if she's ever been convicted of a crime. They have also shared her information with a national database for missing and exploited persons, which will alert them to cases where there could be a connection.

These are just some of the hundreds of unsolved cases going back decades on the Crime Stoppers website and investigators are determined to get justice for the families.

"I encourage people to go to the website, because you never know. There might be someone out there that you might recognize," said Andy Kahan with Crime Stoppers.

Plus, you can remain anonymous and receive a $5,000 reward for information leading to an arrest.

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