LOS ANGELES (AP) _ The prosecution's attempt to pin the torture-murder of a U.S. drug agent on three men is like an effort to catch a greased pig that keeps slipping away, a defense attorney said at the murder trial Friday.

Barry Tarlow accused Assistant U.S. Attorney Jimmy Gurule of altering the facts in the case as the prosecution tried to weave a web of circumstantial evidence around the defendants. And he said key prosecution witnesses were criminals who are lying in an attempt to get lenient treatment.

''No matter how Mr. Gurule tries to twist and distort the evidence, I'm convinced you will see the truth,'' Tarlow said.

Tarlow represents Jesus Felix Gutierrez, 38, who is charged as an accessory to the murder of Drug Enforcement Administration agent Enrique Camarena. He made the greased pig comparison in the first day of closing defense arguments in the eight-week federal court trial.

Camarena was abducted outside the U.S. Consulate in Guadalajara, Mexico, on Feb. 7, 1985. His badly beaten body and that of associate, Alfredo Zavala Avelar were found a few weeks later, buried on a remote Mexican ranch.

The defense lawyer told jurors a folksy tale, saying he was recently complaining about the prosecution's case to a country lawyer friend. The friend, Tarlow said, told him prosecution efforts reminded him of the carnival game where people try to catch a greased pig.

''That pig started to slip and slide and slither away,'' Tarlow said.

Tarlow then attacked the testimony of prosecution witnesses, calling them ''liars, cheats and perjurers,'' contending they were influenced by prosecutors promising lenient treatment in other cases.

He admitted that the jury had a difficult task in trying to determine the guilt or innocence of Felix, an admitted drug trafficker.

''Can a Mexican citizen drug dealer get a fair trial in a horrible case like this one, what with the war on drugs on everybody's mind and with sympathy for agent Camarena?'' Tarlow asked jurors.

Thursday, Gurule called Camarena a heroic law officer who paid ''the ultimate price'' when he was slain while working undercover in Mexico.

Charged with murder in the case are Raul Lopez Alvarez, 28, and Rene Verdugo Urquidez, 36. Felix is accused of helping Mexican drug kingpin Rafael Caro Quintero flee to Costa Rica after the slayings.