A lifetime of frustration caused by his inability to communicate led Joseph M. Mesa Jr. to do some "very bad things," Mesa's attorney said yesterday during opening remarks at his trial in the slaying of two Gallaudet University students.

Ferris R. Bond, at times whispering to the D.C. Superior Court jury, suggested that Mesa robbed and killed Eric Plunkett in September 2000 and Benjamin Varner in February 2001 because he saw sign language "in his head" that directed him to kill them.

Bond said Mesa, who is charged with two counts of felony murder and related crimes, suffers from several mental illnesses. Bond had notified the court that he intended to pursue an insanity defense.

"He couldn't stop," Bond said of the two killings, which occurred in the same campus dormitory. "He wanted to, but he couldn't. That's why these things happened."

For Mesa's trial, court officials have covered the windows of the courtroom door and provided defense attorneys with a partition so that they can have private sign-language communications with their client.

The murder trial was moved from Judge Robert I. Richter's regular courtroom to a larger one to accommodate dozens of spectators, including many members of the victims' families and students from Gallaudet, the prestigious university for the deaf and hard-of-hearing.

Mesa, in a suit and tie, sat expressionless in court yesterday as Assistant U.S. Attorney Jennifer M. Collins told jurors that she and Assistant U.S. Attorney Jeb Boasberg will prove that Mesa was not mentally ill and that he methodically planned and carried out the murders of Plunkett and Varner, both 19, for one reason: money.

Collins said Mesa, now 22, chose Plunkett as his first victim because Plunkett had cerebral palsy and seemed an easy target. She said Mesa made a few "dry runs" to see whether he could sneak into Plunkett's room behind him without Plunkett knowing.

Collins said that in the late evening of Sept. 27, Mesa slipped into Plunkett's room and wrapped his arm around Plunkett's neck until he fell to the floor. He then took Plunkett's dorm room chair and beat him "over and over and over again," Collins said. After that, she said, Mesa took Plunkett's automated teller machine card and later used the card to buy several items at Union Station.

Collins said that Mesa later considered killing his roommate, Chad Shumaker, but decided "it would be too obvious." Instead, she said, Mesa took Shumaker's credit card from an unlocked desk drawer.

D.C. police arrested the wrong person for Plunkett's death, and charges were later dropped. Around Feb. 1, 2001, Collins said, Mesa decided to rob and kill Varner because he knew Varner had money and lived alone. Mesa knew that because Varner was bigger, he would be "harder to kill" than Plunkett, Collins said, and so he used a knife when he attacked Varner in the victim's room.

After the killing, Mesa returned to Varner's room several times to get things he had left behind, including his jacket and the knife, Collins said. But police found other evidence, including bloody shoe prints, and quickly zeroed in on Mesa after a bank videotape showed him cashing a forged check of Varner's for $650.

On Feb. 13, 2001, with police beginning to build a strong case against him, Mesa confessed to police, Collins said. The jury is expected to see the four-hour videotaped statement, which Bond unsuccessfully tried to suppress.

Among the witnesses prosecutors plan to call are several Gallaudet students, officials with the D.C. medical examiner's office, an FBI expert on shoe prints, and Melani de Guzman, Mesa's girlfriend. Prosecutors allege that Mesa wrote her from jail asking her to help with his mental illness defense and to lie in court. In one letter, Mesa wrote that he intended to try to use an insanity defense, Collins said.

"It isn't true, but I hope it will work anyway," Collins read from Mesa's letter.

The first witness called yesterday was Kathleen Cornils, Plunkett's mother, who described her son as frail but intelligent and loving. Grant Greenwalt, a D.C. police officer who processed the Plunkett crime scene, told the jury how the student's chair was used as a weapon in the killing.

Assistant U.S. Attorney Jennifer M. Collins gives her opening statement as Mesa, far left, watches the sign language interpreter. Next to Mesa is attorney Ferris R. Bond, who is pursuing an insanity defense in the two Gallaudet slayings.Joseph M. Mesa Jr. is accused of killing two other freshmen when he was a student at Gallaudet University.