Offensive text messages prompt a review of a decade’s worth of police activity as leadership says trouble is limited to a small group of officers

Prosecutors plan to expand their investigation into a scandal in which San Francisco police officers are accused of sending racist, sexist and homophobic texts and potentially compromising up to 3,000 criminal cases.

A number of texts emerged from court filings during a case in March suggesting the police officers who sent or received the texts may have been prejudiced toward suspects they arrested.

The investigation covers 3,000 cases so far, going back 10 years, and a task force created to carry it out has been bolstered by the addition of three retired judges from outside the area.

Investigators are examining each case to determine whether to overturn those in which convictions were already made and dismiss those currently pending – as well as determine how many other cases may be involved.

While San Francisco’s police leadership has repeatedly insisted that the trouble does not go further than a small group of officers, other city officials are voicing concern that the scandal is a symptom of systemic problems in law enforcement there.

San Francisco district attorney George Gascon said on Thursday that his office’s probe has identified 3,000 criminal cases “so far” that could have been affected by perceived racism, sexism or homophobia by 14 police officers.

“If just one individual was wrongly imprisoned because of bias on the part of these officers, that’s one too many,” he said.

He also announced on Thursday that he was widening the investigation to examine whether a culture of bias exists more widely across the San Francisco Police Department (SFPD).

The offensive text messages in question emerged amid court filings made in March as part of the appeal process in a federal corruption case against former SFPD sergeant Ian Furminger, who was convicted in December 2014 of stealing money and property from suspects, and is serving 41 months behind bars.

Prosecutors have called Furminger a “virulent” racist and homophobe, and said he sent and received texts to and from other officers using derogatory terms, threats of violence, and white supremacist language.

Gascon, who was briefly the police chief in San Francisco, having previously served as assistant chief in Los Angeles, said he feels “terrible” about the scandal, which included cases brought under his watch.

He handed over the top spot at SFPD to Greg Suhr in 2011. Suhr has condemned the texts but has tried to separate the behavior of the officers involved from the that of the force in general.

He called the texts “reprehensible” and “hateful”. Officers, variously, made racist references to non-white people, including African Americans, Filipinos and Mexicans, as “monkeys” and “half-breeds” and discussed lynching and cross-burning.

Suhr has recommended six of the 14 officers be fired and the others be questioned by the police commission, the department’s disciplinary unit.

San Francisco public defender Jeff Adachi, one of the very few elected public defenders in the US, whose office is involved in the investigation, said he hoped to interview victims of alleged discriminatory police actions as well as review documents.

He said the issues underlying the bigoted communications needed to be examined.

“This is a systemic problem we have in San Francisco,” he said.

The latest development in the police inquiry follows another scandal that emerged in March, involving San Francisco sheriff’s deputies, where a number of officers are accused of forcing jailed inmates they were guarding to engage in gladiator-like fights for the staff’s amusement and gambling purposes.