The Little Mouse yearned to be free.

So after three months in prison, Julio Cesar Lara, a 100-pound burglar known as Little Mouse, took his chance one night. With the speed and agility that had earned him his nickname, he slipped past his guards, crawled through the shadows, scurried over a high wall on a makeshift rope and suddenly found himself a free man.

It was three weeks before the police caught up with him. But in the eyes of the Mexican legal system, he had done nothing wrong. Escaping from prison is not a crime in Mexico.

"The law says that all inmates have the right to seek their freedom," said Lara, 27, who is serving three years for burglary but not a single extra day for his jailbreak. "The opportunity presented itself, and I took it."

Mexico's legal system recognizes that all people have a fundamental desire to be free. And it does not punish them for pursuing it, as some inmates recently did by disguising themselves as female visitors and tunneling to freedom using a sardine can as a shovel.

Critics of the law call it one more weakness in a judicial system that is holding back Mexico's efforts to modernize. But those who support the law describe it as a humanitarian measure that respects human dignity.

"The person who tries to escape is seeking liberty, and that is deeply respected in the law," Juventino Victor Castro y Castro, a Supreme Court justice, said in an interview. "The basic desire for freedom is implicit inside every man, so trying to escape cannot be considered a crime."

The same philosophy respects the right to run from the police to avoid capture, said Jose Elias Romero Apis, a lawyer and federal legislator. Likewise, he said, it is not considered perjury in Mexico for people to lie about their guilt on the witness stand.

"It is part of an entire philosophy; the accused is permitted to struggle however he can for his freedom," said Romero, president of the Justice and Human Rights Committee in the lower house of Congress. "Freedom is given priority over other values, including prison security."

There are, however, a few escape clauses. While escaping is legal, prisoners can be charged if they break laws in the process. If they injure someone on the way out, conspire with other prisoners to escape, bribe someone or damage property, they can be charged. But if, like Lara, they simply figure out a way to hop a wall or sneak out a door, they have committed no crime.

"It's an extraordinary law, a charitable and spiritual law," said Sister Antonia, an American Catholic nun who has lived and worked in a Tijuana prison for 25 years. "Every person in their heart yearns to be free."

Some said the get-out-of-jail-free law gives prisoners a chance to get even with an unfair justice system. Mexican prisons are clogged with petty criminals, while bankers and politicians accused of stealing millions stay free. Many said the escape law gives the common man one last shot at beating the system.

"There are a lot of people in jail who shouldn't be," said Javier Reyes, 38, a city public works employee. He said the justice system is especially harsh on the poor and he didn't object to them escaping. "This is a result of the unfairness of the system."

But others said the law, which dates to the 1930s, sends the wrong message, especially at a time when opinion polls show crime is the Mexican public's No. 1 concern. "It's absurd," said Marcelo Ebrard, Mexico City's police chief. "The prisoner is a danger to society if he leaves prison. You cannot value the right of one person over the rights of all the others."

Alejandro Gertz Manero, top public security official in President Vicente Fox's government, called the escape law "nonsense," and said he would like to see it changed. He said officials are working on several proposed changes to the federal criminal code. But Congress would have to approve them, and Fox has had limited success persuading the opposition-controlled legislature to pass his initiatives.

Since his election in 2000, Fox has spent time and money trying to bring Mexico's chaotic prisons under control. When he took office, it was not uncommon for wealthy inmates to buy "weekend passes" to go home for parties. Some built Jacuzzis and tequila bars in their cells. But recently many of those cells have been dismantled, hundreds of corrupt guards have been fired and new surveillance equipment has been installed.

But that has not stopped prisoners from digging and climbing out of prisons -- or just walking out the front door. There are no reliable statistics on escapes, but dozens are reported in the press every year.

Last month, a prisoner walked out of a prison in the state of Jalisco by showing the guards a fake ID brought by a visitor. Also last month here in Mexico City, a convicted murderer in Reclusorio Sur, the prison from which Lara escaped, sneaked out of a prison hospital where he was being treated for a toothache. Still handcuffed, he flagged down a taxi and rode away.

One of the most famous escape artists here, known as "El Tarzan," made big headlines last December by sashaying out of Mexico City's Reclusorio Oriente dressed as a woman in a wig and a dress.

One of the most audacious was a convicted murderer whose wife carried him out of Mexico City's Reclusorio Norte in 1998 in a suitcase she used to lug home his dirty laundry. Prison officials said he dieted until he weighed 110 pounds so he would fit. His nickname before the escape was "The Bullet Eater," but he is now referred to in the local press as "El Samsonite."

He was found nine months later working in a store in Guadalajara and brought back to prison. He escaped again not long afterward and is still free.

The most infamous recent escape was that of Joaquin "El Chapo" Guzman, one of Mexico's most notorious drug lords, who escaped from the maximum-security Puente Grande prison in Jalisco state in January 2001. Guzman bribed guards and prison officials, about 60 of whom are currently on trial. He rode out of prison hidden in a laundry truck and has not been seen since.

If he is found, he will have to finish his 20-year sentence and face bribery charges. But the escape itself will earn him only the admiration of his peers, which is what Lara said he has had since he hopped the wall.

"I'm a hero to the guys who wear beige" prison uniforms, Lara said during an interview in the office of the prison warden, who jokingly calls him "our Spiderman."

Lara said he feels lucky to be alive. Escaping may not be a crime, but prison guards are allowed to shoot and kill anyone trying to escape. Lara dodged a shower of bullets fired by guards who chased him into cornfields.

He has less than two years left on his sentence and said he's looking forward to getting back to running the hamburger stand he operated before. When asked whether he would ever try to escape again, a broad grin crossed his face.

"It depends," he said.

Julio Cesar Lara, a burglar nicknamed Little Mouse, was not punished for escaping from prison.