(a) A person is guilty of failure to appear in the first degree when (1) while charged with the commission of a felony and while out on bail or released under other procedure of law, such person wilfully fails to appear when legally called according to the terms of such person’s bail bond or promise to appear, or (2) while on probation for conviction of a felony, such person wilfully fails to appear when legally called for any court hearing relating to a violation of such probation.

(b) Failure to appear in the first degree is a class D felony.