The prosecution’s case of police brutality against a Fresno police sergeant and three former officers took a major hit Tuesday when jurors heard that the suspect at the center of the case speaks English.

Rolando Celdon’s ex-girlfriend, Veronica Rivera, testified that Celdon speaks “a little bit of English” and understands it better than he speaks it, and pretends to speak only Spanish when it suits him.

Her testimony on behalf of the defense contradicted the prosecution’s contention that Celdon didn’t understand the commands of the English-speaking defendants when they arrested him in October 2005.

Because Celdon declined to surrender, police say, he was punched and kicked, bitten by a police dog, shot with a stun gun and blasted by a bean-bag shotgun.

Prosecutors declined to cross-examine Rivera, who testified in U.S. District Court that she first met Celdon either one or two years before his October 2005 arrest for beating and stalking her — crimes that led to his deportation to Mexico.

        Instead they cried foul, telling Judge Anthony Ishii that Rivera was a surprise witness. “A remarkably low blow,” prosecutor Jared Fishman said.

The judge disagreed after defense lawyers said Rivera was on their witness list. Ishii ruled that Rivera’s testimony was significant to the defendants’ case.

An indictment accuses Fresno police Sgt. Michael Manfredi and former Fresno police officer Sean Plymale of concealing the alleged assault on Celdon by former officers Chris Coleman and Paul Van Dalen. All four are charged with falsifying an official report to obstruct justice. If convicted, each faces up to 20 years in prison.

Officers who witnessed Celdon’s arrest reported what they believed was excessive force. Police Chief Jerry Dyer put Manfredi, Plymale, Coleman and Van Dalen on administrative leave, asked for an FBI investigation of the arrest and eventually fired the four. Manfredi won his job back through an arbitrator and a civil service review board. An arbitrator ruled Plymale should be reinstated, too, but he chose to work for the Madera Police Department. Coleman and Van Dalen left police work.

Because Celdon can’t be found in Mexico, the prosecution’s case is built on the testimony of three Fresno police officers who said the unarmed Celdon posed no threat when Coleman fired six or seven bean-bag rounds at him and Van Dalen kicked him in the side at least twice. They also said they never saw a weapon near Celdon when he was taken into custody.

On the witness stand, Manfredi, Coleman and Plymale refuted the three officers’ version of Celdon’s arrest.

Rivera’s testimony wrapped up the defense case because Van Dalen decided not to testify. Closing arguments will start this afternoon after prosecutors wrap up their evidence.

Throughout the trial, a key issue has been whether Celdon can speak English, or at least understand it. In testimony last week, Plymale admitted that he wrote in his police report that Celdon told him in “plain English” that he had used “cranka,” a slang Spanish term for methamphetamine.

Believing Celdon was a Spanish-speaker, Manfredi testified that when Plymale asked Celdon about using “cranka,” Celdon acknowledged “in the affirmative” with a gesture or head nod.

Another issue is whether the defendants tried to cover up their actions by omitting pertinent details about Celdon’s arrest. For example, Manfredi has admitted that his police report was inaccurate because it said Celdon had armed himself with a stick and bottle to hit the police dog, Tymo. He said the detail about Coleman shooting a stick and bottle out of Celdon’s hands like “Annie Oakley” also was wrong.

Coleman’s police report also said he shot Celdon with a bean-bag shotgun because Celdon was armed with a stick and a beer bottle. Plymale testified he changed his initial report from Celdon holding a beer bottle to him reaching for one.

Defense lawyers contend their clients wrote draft reports. Per department policy, the defendants had the right to amend their drafts before they became official, they said.

Testifying for the prosecution Tuesday, Fresno police officer Pao Xiong and Fresno County deputy district attorney Lisa Sondergaard, however, said draft reports often are used to make important decisions.

Because prosecutors often are under a 48-hour deadline to charge a defendant, Xiong testified that he collected draft and final police reports about Celdon’s arrest and sent them to the District Attorney’s Office for review.

And Sondergaard testified that prosecutors often use Fresno police draft reports in court hearings and trials and to make plea deals. “We rely on them to be truthful and accurate,” she said.