NEW YORK — Some saw him as disagreeable and argumentative, others as quiet and prayerful. He was said to be hard-working but also seemed to simmer with disillusionment over financial and career setbacks.

As Sayfullo Saipov lay in a hospital bed Wednesday, police tried to piece together the life of the 29-year-old man accused of driving a truck onto a New York bike path and killing eight people. A portrait began to emerge of a suspect who was described by the president as an animal and by the mayor as a coward.

Saipov legally emigrated to the U.S. from Uzbekistan, a former Soviet and predominantly Sunni Muslim nation north of Afghanistan that is estimated to have produced hundreds if not thousands of supporters for the Islamic State group and other extremist organizations in Syria, Iraq and Afghanistan.

After arriving in 2010, Saipov made his first home in Ohio, acquaintances said.

Two other Uzbek immigrants, Akhmadjon Kholberdiyev and Mirrakhmat Muminov, came to know Saipov and said they were most struck by how provocative he was.

Sometimes, he would stir quarrels over weighty topics such as politics or the Mideast peace process, they said, but he could also grow angry over something as simple as a picnic.

“He had the habit of disagreeing with everybody,” said Muminov, a 38-year-old from Stow, Ohio, who works as a truck driver, just as Saipov once did.

Muminov described Saipov as “aggressive” and suspected he held radical views, though Muminov never heard him speak of the Islamic State group.

“He was not happy with his life,” Muminov said.

Notes found at the crime scene indicate Saipov acted in the name of the Islamic State group, authorities said.

Kholberdiyev, a groundskeeper at a local mosque, called Saipov quiet and said he came to the mosque to pray every two or three weeks.

According to some media reports, Saipov lived for a time in Kyrgyzstan, another former Soviet nation that borders Uzbekistan, with a sizable ethnic Uzbek minority.

In June of 2010, the area near Osh in southern Kyrgyzstan where he reportedly lived saw violence between Kyrgyz and Uzbeks that left 470 people dead.