The Supreme Court on Monday agreed to decide whether states can use juries made up of only six people in criminal cases, instead of the usual 12. The case puts a Florida chiropractor convicted of practicing with a suspended license in an unlikely leading role in a constitutional clash.

The justices will hear arguments in the fall in the case of Hamed Kian, who argues that a six-person jury violates his constitutional rights.

Florida uses six-person juries for all criminal cases that don’t involve the death penalty. Five other states, Arizona, Connecticut, Indiana, Massachusetts and Utah, also conduct some criminal trials with six-member juries.

The 45-year-old Kian’s license was suspended after three women who were his patients complained he either kissed or touched them inappropriately, according to court records.

Prosecutors sought an indictment after amassing evidence that Kian, who had an office in Jupiter, continued to see patients even after the suspension. He was convicted by a six-person jury.

Kian’s lawyers argue that the smaller jury violates the Sixth Amendment, which guarantees “a speedy and public trial, by an impartial jury of the state.”

The amendment does not explicitly set the size of the jury, but Kian’s lawyers contend that the word jury could only have meant a body of 12 people at the time the amendment was adopted in 1791. Just over 100 years later, the Supreme Court ruled that juries had to have 12 people.