N.J. Stat. § 2B:23-15: Time for making challenges

a. Challenges to jurors may be made at any time before the juror is sworn to try the case.

b. No challenge to a juror may be made after the juror is sworn to try the case unless:

(1) the basis for the challenge could not reasonably have been known earlier to the person making the challenge; and

(2) the challenge is based upon the juror's inability to render a fair and impartial verdict.

Source: 2A:78-9

L.1995,c.44,s.1.