Embattled veteran Houston Police officer Gerald Goines routinely claimed it was too dangerous to knock on a suspected drug dealer’s home.

Goines swore in search warrant affidavits that “knocking and announcing would be dangerous, futile,” because he claimed a confidential informant had seen a gun inside. Those claims led judges to grant no-knock warrants, which accounted for 96 percent of all the search warrants he filed in the last seven years, a KHOU 11 Investigation has found.

But in every one of the more than 100 drug cases based off those warrants, there’s no record of Goines ever seizing a gun after executing a no-knock search warrant.

Those warrants are likely to be part of the District Attorney Kim Ogg’s review of Goines’ past cases that she pledged this week.

That review and a separate criminal investigation stems from Goines’ role in a Jan. 28 narcotics raid in the 7800 block of Harding Street that left two homeowners dead and four HPD officers shot.

Houston Police Chief Art Acevedo accused Goines of lying about a controlled drug buy on a search warrant affidavit to justify the raid. In that affidavit, Goines claimed a confidential informant bought heroin and saw a handgun inside the home, but no heroin and no handgun were ever found.

“If an informant said there was a weapon, why isn’t there a weapon at the crime scene?” said Larry Karson, a former federal agent and Associate Professor of Criminal Justice at the University of Houston Downtown.

KHOU 11 Investigates examined 109 drug cases Goines filed based on a search warrant between 2012 and present day. In every one of those cases in which he claimed confidential informants observed guns inside, no weapons were ever recovered, according to evidence logs Goines filed with the court.

In other no-knock narcotics search warrants filed by different HPD officers, those officers provided detailed descriptions of guns seized after raiding suspected drug dealers’ homes.

Karson said it’s highly unusual not to recover any weapons during a narcotics drug raid.

RELATED: HPD Officer Gerald Goines out of hospital 3 weeks after deadly raid

RELATED: Community board to review deadly drug raid

RELATED: Deadly HPD raid leads to policy changes, FBI civil rights investigation

RELATED: DA to review more than 1,400 criminal cases involving officer who led deadly raid

RELATED: Defense attorney: HPD is 'tainting' investigation into drug raid

“There are a couple of questions that come up, one is the reliability and credibility of the actual informant,” Karson said. “The second issue is it raises the issue of ‘is there an informant?’”

Former HPD officer and DEA agent Jim Dozier also questioned the search warrants filed by Officer Gerald Goines. He is a Sam Houston State University professor, former criminal prosecutor, and Executive Director of the Texas Commission on Law Enforcement.

“I find it highly suspect,” Dr. Dozier said. “No firearms were ever listed in the subsequent inventories returned to the court.”

Acevedo relieved Goines of duty while an internal and criminal investigation continues. Harris County District Attorney pledged to review all of the officer’s past cases throughout his 34-year HPD career.

Criminal defense attorney Nicole Deborde represents Gerald Goines, and downplayed the discrepancies in his past cases.

“None of this appears unusual, concerning or out of the ordinary,” she said.