A 20-year-old Jordanian man caught in an FBI sting trying to blow up a Dallas skyscraper was depressed and slept by his mother's grave after her death from cancer four years ago, his father testified Monday during his son's sentencing hearing.

Hosam Smadi faces up to life in prison after pleading guilty in May to attempted use of a weapon of mass destruction. Under a plea agreement, however, he will likely receive a 30-year sentence and face deportation.

The hearing was expected to continue Tuesday before U.S. District Judge Barbara Lynn at the federal courthouse in Dallas, just blocks away from the 60-story office tower that prosecutors allege Smadi tried to take down. Smadi's public defenders said he may take the stand.

Smadi's father, 60-year-old Maher Smadi, testified that his then-16-year-old son tried to revive his mother even after doctors in Jordan pronounced her dead in October 2006. He said she died from brain cancer, and his son stopped eating after her death.

"Hosam was very affected by his mother's illness and stayed with her at the hospital all the time," Maher Smadi said, testifying in Arabic through an interpreter.

He said he sent his son to the U.S. in March 2007, because their relationship was strained and he wanted the teenager to get an education and "start a new life." The elder Smadi acknowledged that he often beat his son with his fists and a chain, and once tried to run him down with a car. He said his son wasn't very religious or politically motivated.

Maher Smadi said he visited his son in the San Jose, Calif., area less than a year later and was upset to find him smoking, drinking and cursing Islam. The younger Smadi moved to the Dallas area a short time later.

The father acknowledged that his son was a terrorist and said he was embarrassed. He asked prosecutors for leniency.

"I am sure that if he leaves prison now, he would learn from his mistakes and be a good person and get away from bad influences," Maher Smadi testified.

According to the plea documents, Smadi acknowledged leaving what he thought was a truck bomb in a garage beneath the Fountain Place building in September 2009. Smadi said he parked the truck, started a timer connected to the decoy provided by undercover FBI agents, then rode away to watch the explosion.

Smadi dialed a cell phone number from the roof of a nearby parking garage, where he had planned to watch the explosion. The number was supposed to set off his truck bomb. It instead alerted tactical agents hiding in a stairwell, who swarmed the rooftop and arrested the teenager.

Posing as members of an al-Qaida sleeper cell, three undercover FBI employees had monitored Smadi since January 2009. After he shared his plans to blow up the office tower, they helped him secure a truck and fake bomb used to carry out the mission, according to court documents.

FBI officials said that after monitoring Smadi for nine months, agents decided he was a committed would-be terrorist determined to connect with al-Qaida or Hamas. It was fortunate, they said, that the FBI found him first, spewing hatred for America on an extremist website.

But Hosam Smadi's attorneys, like his father, portrayed their client as troubled and depressed. They said he exhibited signs of mental illness when his parents separated and suffered a breakdown after his mother's death.

Doctors also offered opposing views Monday. A psychologist testifying for the defense, Xavier Amador, pointed to interviews in which Smadi said he saw a devil in his home who tied down his hands and grabbed his mouth. Smadi also told the doctor he felt certain he helped his dying mother survive a year longer, thoughts Amador said were "delusional and grandiose."

But prosecutors' psychiatrist, Raymond Patterson, said Smadi "makes up psychiatric symptoms" and seemed to weather the divorce of his parents and death of his mother.

Smadi's father and 12-year-old sister broke into loud sobs when he was led into the courtroom at the start of the hearing wearing an orange prison jumpsuit with his ankles chained together. He was polite, occasionally speaking to the judge.

Mohammad al Zughoul, a former neighbor of the Smadis in Jordan, said in tearful testimony that his neighbors were a happy family until a rumor began about the elder Smadi's wife being involved in an affair. The rumor infuriated Maher Smadi, who acknowledged he began beating his wife and four children.

"Hosam had a lot of suffering," al Zughoul said. "He was taking the responsibility of fighting his father. It destroyed Hosam — this rumor — and I know he is still suffering from that."