An attorney representing a defendant on trial in Sonoma County Superior Court has been arrested on suspicion of possessing methamphetamine at the courthouse.

The arrest of Shell Kaminsky has the potential to spill over into an assault case involving her client and four other defendants, other lawyers involved in the case contend.

Kaminsky, 31, of Brentwood was arrested July 17 after she tried to pass through the north security entrance of the courthouse with drugs, according to Sheriff's Lt. Clint Shubel.

Private security personnel spotted what appeared to be the illegal drug among her belongings, he said.

Everyone entering the courthouse must pass through a metal detector and surrender their purses, briefcases and bags to be examined through an X-ray machine. Shubel wasn't sure whether the packet of drugs was in her purse or briefcase, or what caught the eye of security screeners.

But Kaminsky apparently then tried to leave, he said.

"She started to walk away and one of the security guards followed her and called for a deputy," he said. Sonoma County sheriff's deputies provide law enforcement services at the Santa Rosa courthouse.

A deputy arrested Kaminsky on suspicion of possessing the drugs, a felony, and attempting to avoid the courthouse security screening procedures, a misdemeanor. She was released on $10,000 bail.

Kaminsky, who was admitted to the California Bar just under a year ago, is representing one of five defendants being tried on assault and gang charges in the beating of a man in June 2012 at a car show at Youth Community Park.

Defendant Robert Flett, 27, of Rohnert Park is out of custody during the trial. He could face 20 years or more in prison if convicted of assault causing great bodily injury and a gang enhancement. He also has a prior conviction.

The day she was arrested, Kaminsky's co-counsel, Peter King of Pleasanton, continued the trial in Kaminsky's absence.

She appeared in court on her own case Tuesday with King as her attorney. Prosecutors asked for more time to file charges, and another hearing was set for Monday. King did not return a message seeking comment Thursday.

Attorneys for the other four defendants in the assault case said they are increasingly concerned that Kaminsky's client isn't receiving an adequate defense. Moreover, they said, that could harm their own clients' cases in the eyes of the jury.

George Boisseau, who represents Robert Sandoval, 36, has filed multiple motions for mistrial and has sought to separate his client's trial from Flett's because of Kaminsky.

In part, Boisseau said he argued that Kaminsky is incompetent and unprepared, and that has prejudiced the jury against the other defendants. The other four defense attorneys joined the motions, said Tyler Hicks, who represents Juan Tovar, 20, of Santa Rosa.

"She's way over her head," Boisseau said. "She's not helping her own client, and it's hurting our clients."

Judge Gary Medvigy has denied the motions. Boisseau said the motions may be renewed based on Kaminsky's arrest.

Kaminsky appeared in court Wednesday for trial and told Medvigy she is able to continue representing Flett.

Flett, Tovar, Sandoval, Anthony Cervantes, 25, and Carl Hastie, 27, are charged with assault. All but Sandoval also face gang charges. That trial resumes Tuesday.

(You can reach Staff Writer Lori A. Carter at 762-7297 or lori.carter@pressdemocrat.com.)