A Moroccan on trial for allegedly supporting a cell of the Sept. 11 suicide hijackers was easy to get along with until he fell under the influence of a fellow countryman, who later was convicted on terrorism charges, their former landlord testified Thursday.

Reinhard Martens, who rented defendant Abdelghani Mzoudi (search) a room in his house in late 1996, remembered him as a "very good" tenant until another Moroccan, Mounir el Motassadeq (search), moved in at the start of 1997.

"Mzoudi was quieter than before, he seemed like he could not make his own decisions," Martens testified. "Mounir was not a nice person, very aggressive. In my opinion, he was a religious extremist."

Mzoudi is charged with 3,066 counts of accessory to murder and membership in a terrorist organization for allegedly providing logistical support to the Hamburg Al Qaeda cell (search), which included suicide hijackers Mohamed Atta, Marwan al-Shehhi and Ziad Jarrah.

El Motassadeq, the first Sept. 11 suspect to go on trial anywhere, was convicted in February of the same charges and sentenced to the maximum 15 years.

Martens said he perceived el Motassadeq as a threatening presence.

"He didn't do anything, but I was uncomfortable with him," he said.

Martens, who rented to the two men for several months in late 1996 and early 1997, defended Mzoudi in saying that police misunderstood him when he told them Mzoudi was a "fanatic."

"I meant fanatic in belief," Martens said. "Mzoudi, for me, was a fine person."

Similarly, he said he never told police that Mzoudi and el Motassadeq once told him they were going to kill people, though he signed a police statement saying that. The statement was read out in court Thursday.

"They misunderstood me," Martens testified.

To prove that Mzoudi belonged to a terror organization, the Hamburg state court must show that his friends — such as Atta, al-Shehhi and Jarrah — were an Al Qaeda cell.

Witness Ralf Goetsche, who lived with el Motassadeq in student housing in 1997, described his influence on other Muslims, largely repeating testimony he gave at el Motassadeq's trial.

Another roommate — a "liberal Muslim" from Turkey — became much more devout once el Motassadeq moved in, Goetsche testified.

He said el Motassadeq had regular visitors to their student apartment, including Atta, Jarrah and Mzoudi, who would meet there before going to a mosque.

Recalling an incident in their shared kitchen, Goetsche said el Motassadeq was anti-American, anti-Israel and anti-Semitic.

"He said that what Hitler did wasn't so bad," Goetsche testified. "I asked what he meant, and he said: 'With the Jews.'"