Qualified witnesses have often been permitted to give the opinion that the bullet which killed the deceased was fired from a particular weapon (26 Am.Jur., Sec. 440, p. 460; 23 C.J.S. Criminal Law § 868, p. 82), but it is indeed another matter for a witness to say that, either from scientific knowledge or wide personal experience and from wounds alone, the wounds were inflicted by a particular weapon, here a .32 caliber rifle. The opinion has been permitted by doctors upon pathological examination (State v. Sullivan, 230 Iowa 817, 298 N.W. 884; People v. Wong Chuey, 117 Cal. 624, 49 P. 833; Humphrey v. State, 74 Ark. 554, 86 S.W. 431), but it is not believed that this witness whose special training was as a chemical engineer was qualified by a very limited experience to testify with confident integrity as an expert on this particular subject. In this instance, however, his attempt to qualify and testify was not prejudicial.

The intentional use of a deadly weapon amply infers malice and an intent to kill. State v. Sullivan, 230 Iowa 817, 298 N.W. 884; State v. Mercer, 223 Iowa 1134, 274 N.W. 888; State v. Burris, 198 Iowa 1156, 198 N.W. 82 (and cases there cited). The defendant had told of his intention to shoot the deceased and followed this by doing the very thing he had threatened to do. This would show premeditation and an intent to do the killing.

[5, 6] II. Malice and an intent to kill may be inferred from the intentional use of a deadly weapon in a deadly manner. State v. Sullivan, 230 Iowa 817, 820, 298 N.W. 884. It has been the further holding of this court that upon a plea of guilty of first-degree murder it is necessarily presumed that the act was deliberate and premeditated.

In these cases where a plea of guilty admits all the facts and the sole question to be determined is the degree of the crime and the punishment to be imposed, the appellate court is only concerned with determining whether the discretion of the trial court was judicially exercised. Commonwealth v. Frisbie, 342 Pa. 177, 20 A.2d 285; People v. Hawk, 17 Cal.2d 812, 112 P.2d 225; People v. Lang, 2 Cal.2d 417, 41 P.2d 165; State v. Sullivan, 230 Iowa 817, 298 N.W. 884. There is evidence in the record that appellant was intoxicated.

State v. Wilson, 234 Iowa 60, 91, 11 N.W.2d 737. Since the killing in this case was accomplished by the intentional firing of a pistol at the deceased, malice can be inferred from the use of such weapon unless other circumstances in the evidence rebut the presumption. State v. Decklotts, 19 Iowa 447, 448; State v. Pinkerton, 201 Iowa 940, 208 N.W. 351; State v. Sullivan, 230 Iowa 817, 820, 298 N.W. 884, 886, and cases there cited. In the last-cited case the opinion states:

We have held repeatedly that an intent to kill may be inferred from the use of a deadly weapon in a deadly manner. State v. Sullivan, 230 Iowa 817, 820, 298 N.W. 884, and cases cited. Such intent may be thus inferred though the wound inflicted does not prove fatal.

" In State v. Sullivan, 230 Iowa 817, 820, 298, N.W. 884, 886, we stated: "Sullivan insisted that he did not intend to kill Hart, he only intended to wound him or make him lie down so that Haenze could open the gate.

(internal citations omitted)); State v. Sullivan, 298 N.W. 884, 886 (Iowa 1941) ("If the victim is fatally wounded, the law presumes malice and the intent to kill."). In light of this authority, we conclude the district court did not err in giving the permissive inference instruction.