A United States court on Thursday ruled to keep a 17-year-old Turkish suspect of a deadly hit-and-run accident in Istanbul in detention.

At a hearing in Boston, Massachusetts, Chief Magistrate Judge Donald Cabell ruled for Timur Cihantimur, a U.S. citizen, to remain in custody during the extradition process.

Appearing before the judge for the second time on charges of "involuntary manslaughter and injury," Cihantimur’s lawyers argued that the conditions at the juvenile detention center in the state of Connecticut where their client is being held are not suitable.

They requested for Cihantimur to be placed under house arrest first or, if not, transferred to a more suitable place in Massachusetts.

However, the prosecutor opposed house arrest, saying that Cihantimur posed a flight risk and insisted that the conditions at the detention center were suitable for him.

After an hour-long hearing, Cabell said he needed time to evaluate the substantial amount of information shared by both parties and ruled for the continued detention of Cihantimur.

On March 1, three all-terrain vehicles (ATVs) were traveling in Istanbul's European side district Eyüpsultan when one of them broke down. Cihantimur, who was driving his parents' SUV without a license, crashed into the three ATVs, injuring five people.

One of them, Oğuz Murat Aci, later succumbed to his injuries.

Cihantimur was whisked away from the scene of the accident by his mother, Eylem Tok, in her car and later smuggled abroad, first to Egypt, then to the U.S.

The Boston court also ruled that Tok should be kept in prison.

Türkiye's Justice Ministry has forwarded temporary arrest request documents for their extradition, but the U.S. authorities have not responded.

Pundits say if Cihantimur is tried in the U.S., he could face a harsh sentence since hit-and-run accidents could constitute a felony, which is punishable by up to 15 years in prison in some states.

Should the trial proceed in Boston, the Justice Ministry is expected to provide legal support to the Aci family.

"We’re hoping the best decision comes out of Eylem Tok’s trial," Aci's family told Turkish broadcaster A Haber on Thursday.

"We’re very happy with the U.S. court’s decision (to keep Cihantimur detained)," Aci's mother, Pervin, said. "It set our hearts at rest at least a little bit. Many thanks to those who have stood by us during this period, including President (Recep Tayyip Erdoğan) and Justice Minister (Yılmaz Tunç)."