A Tampa police detective's recent firing could impact quite a few high profile cases.

Eric Houston is under a grand jury investigation and was fired from the department Thursday.

Houston is under federal investigation for what Tampa Police Chief Jane Castor describes as, "criminal" and "egregious" behavior. The firing of Houston is leading to questions about his credibility and the cases he's covered.

Criminal defense attorney, Kevin Hayslett says the greater Houston’s involvement, the greater effect on the case.

“(He can) go forward with the prosecution without this witness and try to prove it and not call him as a witness, that's number one,” said Hayslett. “Number two, they can choose to potentially call him as a witness, but the problem is, that may so taint the case that it overshadows the rest of the case.

“Or number three, they can determine and just out and out dismiss the case."

Houston covered the Cortnee Brantley case. Brantley’s attorney was set to file an appeal Monday.

Cortnee Brantley is the former girlfriend of convicted killer, Dontae Morris, who was found guilty of killing two Tampa police officers.

Brantley was convicted of "misprision of a felony” for failing to tell officers Morris was a felon with a gun.

Now, Brantley's attorney wants to extend Monday’s deadline for filing his appeal of that conviction.

"In that case, this detective kind of had a key role. Some of the issues by which Judge Moody ultimately determined that the law with the evidence supported the verdict, was based upon this detective’s testimony,” said Hayslett.

“If lawyer Irving goes back and says ‘Judge, at the time you’ve made that determination you believe this detective to be credible, and now his credibility is at stake’, it may change the opinion of the judge.”

Chief Castor says Houston’s cases are being reviewed.