Yes, according to sources, the man accused of detonating the bomb during the Boston Marathon, Dzhokhar Tsarnaev, is still in prison. On April 8, 2015, he was found guilty on all 30 counts and given a prison term.
Tsarnaev was sentenced to death. In 2020, though, the appeal was turned down. In March 2022, the initial death sentence was affirmed by the US Supreme Court.
He was then sent back to death row, where he is still incarcerated today. But no date for the execution has been decided upon.