Silvia Guadalupe Perez burst into tears as she named the bitter ingredients of her new life as a widow: three children emotionally adrift, a mounting pile of bills and meager factory wages to pay them.

“I can’t . . . " Perez, 36, said as she sobbed on the witness stand. She took a sip of water and dabbed her eyes with a tissue before turning again to the prosecutor’s gentle questioning.

A few paces away, the man convicted of mowing down her husband with a big-rig truck gnawed his lip and stared a hole into his cowboy boots. By day’s end, a three-judge panel would deliver his punishment.

Courtroom dramas such as this sentencing are standard fare north of the U.S. border. But what’s happening in the northern state of Chihuahua amounts to a revolution in Mexican justice. Far-reaching legal reforms have brought U.S.-style trials to the border state, providing a glimpse of the kind of change that experts say is needed throughout Mexico to rescue an opaque and graft-laden justice system besieged by organized crime.

Chihuahua has overturned centuries-old legal traditions and opened courts to public scrutiny as never before.

The reform effort in the state, whose largest city, Ciudad Juarez, has been racked by gruesome drug killings, comes as the government of President Felipe Calderon is locked in a war with narcotics traffickers. Many analysts say success against organized crime hinges on building a new judicial system and cleaning up corrupt police agencies.

Chihuahua’s overhaul has attacked an ossified judicial system that many Mexicans long ago stopped trusting. In contrast to U.S. practice, detainees in Mexico are treated as guilty until proven innocent, and often are beaten until they confess. Trials are usually held behind closed doors and in writing, rather than in person. Witnesses rarely confront assailants in court.

Moreover, trials in other parts of Mexico can drag on for years, slowed by endless injunctions that are a favorite weapon of the rich, and by a clogged court calendar overloaded with small-potatoes cases, such as routine car accidents, which are treated in this country as crimes.

Since unveiling its new system two years ago, Chihuahua court officials have experimented with legal tools untried in Mexico: plea bargains, mediation, suspended sentences and probation. These mechanisms, familiar in the United States, are considered daring innovations to streamline Chihuahua’s courts, officials say.

“You have a faster, more open system that is completely transparent,” said Margarita Romero Sanchez, one of the state’s 72 judges who were trained for oral proceedings by legal experts from foreign countries, including Chile, Costa Rica and the U.S.

The reforms aim to fix a system in which only one or two of every hundred crimes result in prosecution and conviction.

Similar programs have been adopted by some other states, such as Baja California, Oaxaca and Zacatecas. Last year the Mexican Congress approved oral trials in the federal courts as part of a judicial reform package that required changing the constitution.

Reform advocates contend that fair trials will force police to act more professionally. Slipshod police work due to poor training, thick caseloads and neglect remains a weak spot in the criminal justice system, officials acknowledge.

The changes also could help win the trust of the public. By this thinking, a robbery trial in Chihuahua represents a blow against impunity across Mexico.

“These behind-the-scenes criminal justice reforms are really what are going to make the difference in the long run,” said David Shirk, who tracks law enforcement trends in Mexico and directs the Trans-Border Institute at the University of San Diego.

Chihuahua’s reforms, spearheaded by Gov. Jose Reyes Baeza after his 2004 election, rolled out gradually, starting in January 2007 in the capital, also named Chihuahua. Oral trials began in Ciudad Juarez a year later and in the rest of the state in July.

In the capital’s main courthouse, prosecutors and defense attorneys joust in public in sleek, wood-paneled courtrooms equipped with cameras that beam proceedings to a video control room. Information is recorded digitally; the piles of files that once filled entire rooms are nowhere in sight.

Perhaps the most basic change is that suspects are presumed innocent, reversing the inquisitional system brought by Spanish colonizers. The arrested are no longer tossed straight into jail, but can remain free while prosecutors present evidence in hopes of winning an indictment.

Many residents question whether the reforms that include more rights for the accused may be to blame for a yearlong wave of killings in Chihuahua, especially in Ciudad Juarez. A little less than a year after the reforms debuted in the capital, lawmakers responded to public pressure and made more suspects subject to incarceration before appearing in court.

But killings tied to drug trafficking are federal offenses. Robberies, assaults and murders not linked to organized crime are handled in state courts.

Critics “don’t distinguish,” the state’s attorney general, Patricia Gonzalez, said in an interview. “They believe it could be because of this new criminal justice system.”

All agree that the flexibility of the new system is one of its best points. Having new ways to adjudicate cases, such as letting defendants plead guilty in return for lesser punishment, means that relatively few of them go through a long trial.

Of 1,112 cases filed in Chihuahua city last year, only eight went all the way to an oral trial. Six of those ended in conviction. Ciudad Juarez had 1,253 cases, but only six trials. In both cities, about a quarter of all cases ended in a plea bargain. Many other suspects received probation or had charges dropped after agreeing to compensate the victim.

Court officials say they want to keep the docket clear of minor matters. Now many cases are mediated through the state attorney general’s office, allowing parties to reach a court-supervised deal instead of trial.

Judge Romero was trying to nudge one such case toward mediation on a recent day. A mechanic charged with smashing his pickup truck into a car sat glumly as Romero called a new hearing in six months. That is enough time, she said later, for the two sides to agree on a fair damage estimate, and for the defendant to avoid a possible five-year prison term.

“The trial under the old system would take three years. What good does it do to wait that long?” said Romero, 36. “The victim gets no satisfaction.”

Some wrongs can’t be fixed with a handshake.

Perez, the widow with three children, acknowledged on the stand that her husband’s killer had offered to pay her $3,100. But funeral costs alone added up to $2,000, she noted.

Instead, the homicide case went to trial. Cuitlahuac Davila, 49, was convicted of running over her husband with a tractor-trailer after a booze-soaked argument.

The sentencing hearing, in front of a nearly empty gallery, lasted 90 minutes. Perez, bundled in a quilted nylon parka, cried some more and then took a seat next to the prosecutor. The three judges, in suits and ties, called a recess to decide the sentence.

Their answer came 10 hours later: Davila was to serve eight years in prison and pay $4,700 to the widow. Case No. 30/2008 had ended a year after its start, lightning-fast for Mexico. The sentence was read in open court -- the way it is done in Chihuahua these days.

ken.ellingwood@latimes.com