The in-laws of dead Boston Marathon bombing suspect Tamerlan Tsarnaev have given evidence before a federal grand jury.
Judith and Warren Russell declined to comment as they entered the grand jury room at the US District Court in Boston. Their daughter Katherine was married to Tsarnaev.
Authorities say Tsarnaev is one of two brothers responsible for the April 15 bombings that killed three people and wounded more than 260 others at the finish line of the Boston Marathon. He died after a gunfight with police.
A lawyer for Katherine Russell and her family has said she did not suspect her husband of anything before the bombings. Lawyer Amato DeLuca said Ms Russell's parents also knew nothing about their son-in-law's alleged involvement until after he was publicly identified by authorities.
The US Attorney's office would not comment on whether Katherine Russell or anyone else was being investigated or why a grand jury continued to meet after four people had already been indicted.
Josh Dratel, a lawyer who represents Ms Russell and her family, said her parents appeared after being subpoenaed to give evidence and said they "told the truth". Mr Dratel said he has been told by prosecutors that Ms Russell was not a target of the investigation.
Tamerlan's brother Dzhokhar was indicted on 30 counts in June and faces the possibility of the death penalty. Three of his friends were also indicted for allegedly lying to investigators or trying to cover up his role after the bombings.
Mr DeLuca has said Ms Russell did not suspect her husband of anything before the bombings and nothing seemed amiss in the days after. He said her parents also knew nothing about their son-in-law's alleged involvement until after he was publicly identified by authorities.
There are many unanswered questions about what Ms Russell knew or did before and after the bombings. The couple lived in the Tsarnaev family's cramped Cambridge apartment, where authorities have said the brothers assembled the bombs. Ms Russell has never spoken publicly, although Mr DeLuca has said she was working 70 to 80 hours a week as a home health aide and had no reason to suspect her husband of anything. Mr Dratel said the grand jury's investigation "is not necessarily an investigation of Katherine...It's an investigation of the entire situation".
Ms Russell has never been charged with any wrongdoing but she has been questioned several times and was followed for several weeks after the bombings by federal authorities. Federal officials ended surveillance of her home around the time her brother-in-law was indicted, according to neighbours.