"His story didn’t match up based on what I saw -- physical evidence at the scene -- and based on the story that he told me," Gantt said. "The mere fact that he was living in East Oakland and said he walked to the store without his gun, without his badge, barefoot, when he doesn’t smoke -- it just doesn’t make sense to me."
But he wouldn't have much opportunity to pursue his suspicion. He said former homicide Lt. John Lois removed him from the case in the middle of questioning O'Brien, who joined the OPD in 2013, and after Basa said he was pressuring the rookie officer too much.
"I saw Sgt. Basa inside John Lois' office speaking with him," Gantt said. "Lois called me into his office and he said 'Hey, I'm taking you off the case,' and I said, 'Why? What did I do?' He said 'I just don't want you to work the case anymore.' "
Without Gantt's involvement, the department determined Huerta-Lopez had killed herself, a finding recently bolstered by the Alameda County District Attorney's Office.
Gantt went on to work other cases but, he said, OPD's homicide section was suddenly a lot less friendly to him.
"The thin blue line is alive and well, and once you step over that line then you become an outcast," Gantt said. He filed a complaint after several homicide inspectors viewed his personnel file -- which is generally confidential. But there were no repercussions. Gantt transferred out of the homicide section less than two months after Huerta Lopez's death.
He then brought another complaint to internal affairs, this time for receiving what he described as racist text messages from a superior officer. Again, his complaint had no impact.
"They said that the investigation was unfounded," Gantt said. "So, unfounded about people looking in my personnel file, which I have proof that they did, but OPD said it didn’t occur. I have proof that I received racist text messages. They said that it didn’t occur. And as far as a hostile work environment, now-Deputy Chief John Lois created a hostile work environment for me while I was in the homicide section."
About a year after Gantt transferred from homicide, Brendan O'Brien killed himself in the same apartment where Huerta-Lopez died. He reportedly left a suicide note indicating inappropriate relationships between other officers and the teenage daughter of an OPD police dispatcher. At the time the teenager, Jasmine Abuslin, went by the name Celeste Guap.
OPD's investigation into potential crimes or misconduct stayed quiet until summer, when it led to a series of police chief resignations. Five current and former Oakland officers face criminal charges related to their relationships with the now 19-year-old woman, including some felonies for engaging in sex acts with her before she turned 18.
"A lot of people knew about that, but the only people you see getting in trouble are officers and a sergeant," Gantt said. "There’s a lot of people way above them that knew and didn’t say something, and we’re all mandatory reporters. So I don’t see why one sergeant and these officers are in trouble and everybody else gets to skate, so to speak."
Gantt's attorney, Dan Siegel, said he hopes his client's claim will lead to the release of information still obscured about the investigation, including O'Brien's suicide note.
"The main issue here is a case that will clear Sgt. Gantt’s name and hopefully bring light on what’s going on in the department," said Siegel, a longtime critic of the OPD who ran unsuccessfully for mayor in 2014.
Tuesday's claim isn't Gantt's first tussle with OPD. He was fired after the department found he impeded a 2004 rape investigation, according to the Mercury News. But he challenged the decision and was reinstated by 2006.
The Police Department deferred questions about Gantt's allegations to city officials. A spokeswoman for Mayor Libby Schaaf responded in a written statement Tuesday that the city is "legally prohibited from disclosing personnel information about any police officer and we do not comment on pending litigation."
"There is a clearly defined legal process for handling these claims and we welcome the opportunity to present the full set of facts," the statement says.
Gantt's problems with the OPD didn't end when he left the homicide section. He was publicly accused in June of improperly sharing information from at least one homicide investigation, which the Alameda District Attorney's Office investigated and found no criminal wrongdoing.
"They damaged me by putting out all those false allegations about me," Gantt said. "They know I’m getting ready to retire. They know I’m ready to go. This is, I think, because I filed those complaints. This is a way for them to get me on my way out the door."