(1) acting with the kind of culpability required for the offense, he causes or aids an innocent or nonresponsible person to engage in conduct prohibited by the definition of the offense;

(2) acting with intent to promote or assist the commission of the offense, he solicits, encourages, directs, aids, or attempts to aid the other person to commit the offense; or

(3) having a legal duty to prevent commission of the offense and acting with intent to promote or assist its commission, he fails to make a reasonable effort to prevent commission of the offense.

(b) If, in the attempt to carry out a conspiracy to commit one felony, another felony is committed by one of the conspirators, all conspirators are guilty of the felony actually committed, though having no intent to commit it, if the offense was committed in furtherance of the unlawful purpose and was one that should have been anticipated as a result of the carrying out of the conspiracy.