.Documents reveal San Rafael cop had previous credibility issues

boheme magazine e-edition

The Marin County district attorney knew that San Rafael police officer Brandon Nail had credibility issues long before he beat and bloodied a local gardener during questioning about an open container of beer, according to an internal police memo.

This is just one of many disclosures in the 89 documents, audio files and videos related to the City of San Rafael’s internal investigation into a July 27, 2022 use of force incident. The files were released last week, after a Marin County judge ordered San Rafael to disclose the records in response to three lawsuits that sought to obtain the information under the California Public Records Act. All the materials are now posted on the police department’s website.

A review of the records pulls back the curtain on how the police department manages complaints about its officers. Unless police misconduct falls into certain categories, officers’ records are confidential. These investigative records became public because the use of force resulted in “great bodily injury.”

Nail, who was fired earlier this year, has been charged with two felonies—assault under color of authority and making false statements in a crime report—for his role in the incident. His co-defendant, former police officer Daisy Mazariegos, was also terminated from the department and faces the same charges.

Apparently, this is not the first time that the district attorney has accused Nail of improper reporting. In an Aug. 25, 2022 memo about the use of force incident, San Rafael police Lt. Lisa Holton documented a previous conversation with Chief Deputy District Attorney Dori Ahana.

The DA’s office was questioning Nail’s credibility in the use of force case, but they already had concerns about him stemming from a July 2020 case, according to Holt’s memo.

“DA Ahana told me that their office had a prior issue with inconsistencies in a report written by Officer Nail,” Holton stated in the memo. “In the prior case DA Frugoli decided to handle the issue by speaking to Chief Bishop about it and letting the police department handle it internally.”

Attorney Charles Dresow, who represents Julio Jimenez Lopez, the victim in the use of force incident, is deeply troubled by the information in the memo. 

“It begs the question whether the policies of the DA’s office allowed an officer with credibility problems to remain on the street and a member of the public was injured because of it,” Dresow said. “This is why it’s so important for the public to have access to records of officers with credibility or misconduct issues.”

After the 2020 case, Frugoli could have placed Nail on the Brady list, the prosecutor’s list of officers with credibility issues. This would have required the DA’s office to inform the defense in all cases involving Nail as a witness of his previous conduct. 

Yet, Frugoli failed to do so. She justified her decision in an email to the Pacific Sun, stating that the inconsistencies in Nail’s report of the prior case did not include false statements. 

Two years later, Frugoli again had to review Nail’s conduct—his use of force against Jimenez Lopez and the discrepancies between his police report and the videos from body-worn cameras. This time, Frugoli took more definitive action.

“The Brady committee decisions are made on a case by case basis and consist of a team of experienced prosecutors,” Frugoli said. “This committee determined that Officer Nail would be put on a notification/disclosure list.” 

In June 2023, the DA’s office finished its investigation of the use of force incident and filed criminal charges against Nail and Mazariegos for assaulting Jimenez Lopez and falsifying their police reports. Frugoli stated that there is evidence to prove the charges beyond a reasonable doubt.

The DA’s conclusions conflict with those of Paul Henry, the independent investigator hired by San Rafael to conduct an internal investigation. Henry’s reports, issued March 29, 2023, were part of the records released last week.

Mazariegos and Nail did not use excessive force against Jimenez Lopez, according to Henry. Additionally, Henry found there was insufficient evidence to determine whether their police reports accurately described the facts.

The use of force incident began when Mazariegos contacted Jimenez Lopez and his two friends on Windward Way in the Canal area about drinking in public. Mazariegos instructed the men to sit on the curb and asked for their identification. 

Henry found that Mazariegos didn’t attempt to develop a rapport with Jimenez Lopez and that her “demeanor was stern, challenging and officious.” The situation escalated when Nail responded to “provide cover” for Mazariegos. 

Jimenez Lopez stood to retrieve his ID, and Nail told him to “sit the fuck down.” Although he obeyed, Mazariegos once more requested his ID and he stood again. The officers told him again to sit down and then grabbed Jimenez Lopez’s arms to handcuff him.

“Both officers expressed a concern that Mr. Lopez may try to flee the area or assault one or both police officers,” Henry stated in his report.

Despite their concern, Mazariegos and Nail never patted down Jimenez Lopez or his two friends to search for weapons. In fact, one of the men, also a gardener, had gardening shears on his belt, which was discovered by another officer who responded to the scene after the use of force.

Holton reviewed the body-cam videos and did not agree that Jimenez posed a threat. “Jimenez [Lopez] was not being aggressive or giving any indication that he was planning to run or fight the officers,” Holton wrote in her Aug. 25, 2022 internal memo.

Henry’s and Holton’s perspectives diverged on Jimenez Lopez’s actions when the officers tried to handcuff him. While Holton indicated that Jimenez Lopez “tenses up,” Henry stated that Jimenez Lopez resisted the officers, necessitating the use of force.

That force included Nail tripping Jimenez Lopez and punching him in the face, the records and videos show. Jimenez Lopez suffered a broken nose, concussion and a torn labrum in his shoulder, which required surgery.

The officers arrested Jimenez Lopez, stating in their police reports that he attempted to put Nail in a headlock. Nail also said that Jimenez Lopez hit him in the head several times. However, the body cam footage did not show Jimenez Lopez putting Nail in a headlock or hitting him.

The DA’s office filed charges against Jimenez Lopez, but subsequently dropped them after watching the videos.

Corporal Oscar O’Con, the supervisor who responded to Windward Way after the incident, signed off on the officers’ reports prior to watching the videos. Henry also investigated O’Con.

Although O’Con kept his body-worn camera on when he interviewed Jimenez Lopez and the other two men at the scene, he turned it off when interviewing Mazariegos and Nail about the use of force. It took O’Con almost a month to write the use of force report, leaving his superiors in the dark about the incident.

Ultimately, Henry found that Mazariegos, Nail and O’Con violated some department policies. 

Mazariegos and Nail failed to employ de-escalation techniques and didn’t consider alternative tactics to use of force, according to the report. Henry also stated that use of force could have been avoided, and Mazariegos and Nail handled the incident poorly. Both officers brought discredit to the police department, Henry said.

O’Con’s list of violations included negligence of duty and unsatisfactory work performance. Henry summed it up by stating that O’Con did not “adequately supervise an incident involving a use of force.”

Police Chief David Spiller terminated Mazariegos in May 2023, and Nail was fired the following month. Nail, who was with the department for five years, is appealing the decision; however, Mazariegos was let go during her probationary period, and has no right to contest.

For O’Con’s role in the incident, Spiller meted out a four-day unpaid suspension.

As Henry repeatedly indicated in his report, use of force situations evolve rapidly. Officers are forced to “make split second decisions,” he said.

During lengthy interviews with Mazariegos and Nail, Henry tried to understand the officers’ mindset during the incident. Both indicated they believed there was no alternative but to use force against Jimenez Lopez, who was stopped for a minor infraction.

We may never know what the two officers were actually thinking. However, Mazariegos did impart some interesting information to Henry during her interview. 

Mazariegos and Nail were “beat partners” and had spoken at the beginning of their shift, discussing whether they were caught up on their paperwork. Both were.

“So we decided to go and try and get an active arrest,” Mazariegos said.

Indeed, they did. 

Lt. Holton Memo

Paul Henry’s Interview of Daisy Mazariegos

Paul Henry’s Interview of Brandon Nail

Paul Henry’s Interview of Oscar O’Con

Nikki Silverstein
Nikki Silverstein is an award-winning journalist who has written for the Pacific Sun since 2005. She escaped Florida after college and now lives in Sausalito with her Chiweenie and an assortment of foster dogs. Send news tips to [email protected].


  1. Of course.. a piece written by the cop hating homeless loving Nikki. No surprise she does a hit piece. Her buddies are the ones that tried unsuccessfully to rid Marin of its police force.

    There is a good reason people line their bird cages with the Pacific Sun.

    • Please sign me up for the newsletter - No
    • If what you are saying is true then please back it up with evidence and a coherent argument to support your claims. Thanks.

      • Please sign me up for the newsletter - Yes
      • Terry – a fact driven story seem to really bother you.

        Keep telling the truth Nikki!

        • Please sign me up for the newsletter - Yes
  2. Thanks again Nikki for providing us with an in depth look into this investigation and law suit. It is very clear that the behavior of the two officers was wrong as determined by D.A. Frugoli and investigator Henry. The costs to the taxpayers in this case I’m sure are astounding. The thought that comes to mind for me is: What went down back in the day? I can only imagine how many false reports were filed in order to “bust” people. I fully realize that there are plenty of bad folks out there and there always is a need for police to keep the order but Nail and Mazariegos lied to support their narrative. THAT is a fact that cannot be denied. I do feel bad for the law abiding good officers that protect and serve the public but are sullied every time their fellow officers behave in a less than professional manner. Keep up the good reporting Nikki, we do appreciate you.

    • Please sign me up for the newsletter - Yes


Please enter your comment!
Please enter your name here

Pacific Sun E-edition Pacific Sun E-edition