The defendant appeals his conviction for forgery and attempted forgery, § 40A-16-9(B), and § 40A-28-l(C), N.M.S.A.1953 (2d Repl.Vol. 6). We reverse on the basis of one of the claimed errors and do not reach the merits of the others.
The state began its presentation with the testimony of the woman whose checks were forged, Margaret Benavidez. She *425testified that she had entered a grocery store, leaving her purse in her car and that when she returned to the car her purse was missing. She suspected three men sitting in a car parked next to hers; she questioned them but declined their offer to let her look in their car. At trial the defendant was identified as one of the men who had been in the car. The record reveals no prosecutions for this theft. Other witnesses for the state included two hank tellers, who said the defendant had driven a car to the drive-in lanes of their respective branches. One witness stated that the woman in the passenger side of the car had handed the defendant a check which he had put in the drawer next to the driver’s seat; the other testified to receiving the check in the pneumatic cylinder which the bank used for the distant lanes.
The defendant’s main witness was the woman who had been in the passenger side of the car, Ramona Murphy. She is an ex-girl friend of the defendant who was not tried in this case because of a guilty plea in another case. Her testimony was that a Ramon Madrid, who said he had “pulled a job”, had given her the checks; that she forged Ms. Benavidez’ signature on them; that the defendant knew nothing about the forgeries; that she had handed the checks face down to him when she gave them to him to put into the cylinder and the drawer; that he had not seen the signatures on them; and that she had told him the checks were for welfare and babysitting.
The crime of forgery includes “ . knowingly issuing or transferring a forged writing with intent to injure or defraud.” Section 40A-16-9, supra. The jury was also instructed that one could be convicted of the principal crime if one “ . procures, counsels, aids or abets in its commission and although [one] did not directly commit the crime . . . .” Section 40A-1-14, N.M.S.A.1953 (2d Repl.Vol. 6).
There are apparently two theories on which the defendant could have been found guilty of forgery. The first is that by inserting the checks into the cylinder he transferred a forged writing. The second is that he procured the checks for Ms. Murphy and helped her get them cashed and therefore was an accessory.
The evidence is insufficient to support a finding that the defendant inserted the checks into the cylinder with the intent to commit a forgery. Ms. Murphy, whose testimony is uncontradicted by direct evidence, testified that the defendant did not know that the checks were forged. The only fact upon which a finding of defendant’s guilty knowledge can be based is the defendant’s presence in a car next to Ms. Benavidez’ at the time that she thinks the checks were stolen. The inference of guilty knowledge from these circumstances requires the inference that the checks were stolen by someone in the car and that the defendant knew that the checks Ms. Murphy later passed to him were the same checks. Thus, it is only by the impermissible device of basing the inference of knowledge on one of these conjectures that the jury could conclude that the defendant knew the checks were bad. See State v. Peden, 85 N.M. 363, 512 P.2d 691 (1973) ; DeBaca v. Kahn, 49 N.M. 225, 161 P.2d 630 (1945). The other evidence cited to indicate that the defendant had knowledge that the checks were forged, such as his relationship with Ms. Murphy and his driving her to two different branches of the same bank within three hours, does not form a sufficient basis upon which to rest a conclusion of guilty knowledge. We are aware that “[g]uilty knowledge is rarely susceptible of direct and positive proof and generally can be established only through circumstantial evidence. . . . ” State v. Zarafonetis, 81 N.M. 674, 472 P.2d 388 (1970). However, this does not remove the obligation we have to examine the evidence to determine whether there was substantial evidence to support a finding of intent. The comparison of this case with another with similar facts is instructive. In State v. Martinez, 85 N.M. 198, 510 P.2d 916 (Ct.App.1973), the defendant was *426convicted of aiding and abetting a forgery. The defendant had driven a woman to the drive-in window of the bank. The woman identified herself by the name of the woman whose checks were forged. The teller then questioned the defendant as to the identity of the woman. The defendant assured the teller that he knew the woman personally and then endorsed the forged checks. The defendant’s intent to defraud was revealed by his misrepresentation of the woman’s identity. In the case before us there is no act which is similar to this assertion nor is there any other comparable evidence of the defendant’s knowledge.
Similar difficulties arise when we trace through the theory that the defendant aided and abetted the commission of the forgery. The fact that the defendant accompanied Ms. Murphy at the time that she cashed the checks is not sufficient to support a finding of aiding and abetting, for “[m]ere presence, of course, and even mental approbation, if unaccompanied by outward manifestation or expression of such approval, is insufficient. . . . ” State v. Ochoa, 41 N.M. 589, 599, 72 P.2d 609, 615 (1937). Thus the theory that the defendant aided and abetted Ms. Murphy is presumably based on the belief that the defendant procured the checks for Ms. Murphy and helped her cash them. In support of this theory there is evidence that the defendant was in the car next to Ms. Benavi-dez’ at the time she thinks her purse was stolen. There is also a statement of the defendant, repeated at trial by a police officer, that he had been present when Ms. Benavidez questioned the men in the car about the theft of the checks.
All of this evidence that points to the defendant as the one who took the checks and gave them to Ms. Murphy is circumstantial. When all of the evidence which establishes the different elements of a crime is circumstantial (See State v. Peden, supra) that evidence “ . . . must be incompatible with the innocence of the accused upon any rational theory and incapable of explanation upon any reasonable hypothesis of the defendant’s innocence. . ” State v. Easterwood, 68 N.M. 464, 466, 362 P.2d 997-998 (1961).
This rule for the treatment of circumstantial evidence is really nothing more than an application of the substantial evidence rule. State v. Madrid, 83 N.M. 603, 495 P.2d 383 (Ct.App.1973). Our concern is whether the evidence is sufficient to allow an inference of the disputed act and intent from it, with special rules of inference imposed on the jury when the evidence is circumstantial. See State v. Elam, 86 N.M. 595, 526 P.2d 189 (Ct.App. 1974). In this case we do not think the evidence was sufficient to allow a finding that the defendant aided Ms. Murphy by procuring the checks for her because there are too many other explanations which account for Ms. Murphy’s possession of Ms. Benavidez’ checks.
In reaching this conclusion the promise that we can be controlled by the myriad of New Mexico cases considering the substantial evidence rule and circumstantial evidence is tenuous. Therefore, we will not review the facts in these cases and draw strained comparisons but will rather state that our review of these cases satisfies us that the amount and quality of evidence in this case is far below that found insufficient in several other cases.
The judgment will be reversed and the cause remanded to the district court with instructions to discharge the defendant.
It is so ordered.
SUTIN, J., concurs.
HERNANDEZ, J., dissents.