As the massive manhunt for Dzhokhar Tsarnaev continued on Friday, details of the younger of the two suspects in the Boston marathon blast began to emerge. According to a former classmate, he was "a sweet guy"; a neighbour said he was a "lovely, lovely kid".

The 19-year-old, who is thought to have carried out the Boston marathon bomb with his older brother, was described by friends and family as very different to the 26-year-old Tamerlan. Where Tamerlan is reported to have told people that he didn't have a "single American friend", Dzhokhar was portrayed as a sociable member of his school community.

Rebecca Mazur, who studied with Dzhokhar at the Cambridge Rindge and Latin School, told Buzzfeed that he was "a sweet sort of guy". "He was a familiar part of the community, he didn't isolate himself," Mazur said. Likewise, a neighbour to the suspect said there was seemingly no indication of anything wrong. Larry Aaronson told CNN: "He was a lovely, lovely kid. He was a wonderful kid … he was never in trouble."

Aaronson said Dzhokhar was pleased to have put his past in the troubled North Caucasus behind him. "He was so grateful to be here and to be in school and so grateful to be accepted," he said. The brothers' uncle, Ruslan Tsarnaev, said on Friday that Dzhokhar was born in Dagestan. One report, in the Wall Street Journal, claimed the two brothers had come to the US separately, one in 2002 and one in 2004.

According to Tsarnaev's account on the Russian social networking site VKontakte, he attended School No 1 in the Russian town of Makhachkala from 1999 to 2001. An acquaintance from high school told the Guardian that Tsarnaev appeared to be a "very relaxed" person, in contrast to his brother. At Cambridge Rindge and Latin School, he was remembered as a keen wrestler and a sociable student. Online pictures show a smiling Dzhokhtar apparently at his school prom.

Those who remember him at the school suggest he was well integrated in its diverse community. "[Dzhokhar] wasn't 'them'. He was 'us'. He was Cambridge," Andrea Kramer – whose son studied with Dzhokhar – told the Wall Street Journal.

Tsarnaev appears to have been a good student, apparently receiving a $2,500 scholarship from the city of Cambridge in 2011, to pursue a college education. He was named a wrestling all-star at his high school in the same year. On his VKontakte page, Dzhokhar says he considers "career and money" most important in life.

The page says Dzhokhar speaks English, Russian and Chechen, and belongs to a number of groups devoted to Chechnya. He was born on 22 July 1993, just before a fierce battle for independence broke out in the republic of Chechnya, which attempted to secede from Russia in the wake of the Soviet Union's collapse. Over time, the independence movement grew increasingly Islamist in character.

On his VKontakte page, Dzhokhar lists his world view as "Islam" and follows several pages devoted to the topic. He also lists one of his favourite songs as Hey Sexy Lady, by Shaggy.

Dzhokhar's father would not accept Friday that his younger son was involved in the crimes he is said to have carried out. Anzor Tsarnaev told the Associated Press his son was a smart and accomplished young man. Speaking from Makhachkala, the capital of Dagestan, he said: "My son is a true angel. Dzhokhar is a second-year medical student in the US. He is such an intelligent boy. We expected him to come on holidays here."