Appellant Allan Frank Davis, an inmate of the Cummins Unit of the Arkansas Department of Corrections, seeks a writ of habeas corpus pursuant to 28 U.S.C. § 2254 and appeals the district court's1 denial of relief. For the reasons indicated below, we reach the merits of claims which have been presented to state courts, reversing and remanding the remainder for exhaustion of state post-conviction remedies.

Appellant was tried for first-degree murder of his wife in Circuit Court of Garland County, Arkansas, and was convicted despite a defense of not guilty by reason of insanity. His conviction was upheld by the Supreme Court of Arkansas. Davis v. State, 246 Ark. 838, 440 S.W.2d 244 (1969). Eight years later, without resort to Arkansas post-conviction remedies, appellant in 1977 filed the present petition for federal habeas corpus relief.

Appellant's pro se petition2 realleged four claims previously considered by the Arkansas Supreme Court.3 Davis v. State, 246 Ark. 838, 440 S.W.2d 244 (1969). Of these claims, the striking of jurors with scruples against capital punishment was rendered moot by the commutation of appellant's sentence of death to life imprisonment.

Two of the other three claims are not cognizable under 28 U.S.C. § 2254, which affords relief to persons held "in custody in violation of the Constitution or laws or treaties of the United States."

The admissibility of evidence is usually a matter of state law and procedure and does not involve federal constitutional issues. A justiciable federal issue is presented in a habeas corpus proceeding only where trial errors infringe upon a specific constitutional protection or are so prejudicial as to amount to denial of due process. Cooper v. Campbell, 597 F.2d 628, 632-33 (8th Cir. 1979), Citing Hogan v. Nebraska, 535 F.2d 458, 460 (8th Cir. 1976); Nelson v. Hutto, 597 F.2d 137, 138 (8th Cir. 1979); Schleicher v. Wyrick, 529 F.2d 906, 911 (8th Cir. 1976).

In the present case, appellant objects to the introduction of photographs of the murder scene and of his mother-in-law's body. The murder of appellant's wife, for which he was convicted, and the shooting of his mother-in-law were part of a single occurrence. The photographs in question were admissible both to explain what had occurred and for the purpose of showing malice. We hold that the introduction of these photographs into evidence does not rise to the level of constitutionally cognizable error. Cooper v. Campbell, supra, 597 F.2d at 632-33.

Appellant next objects to "certain (jury) instructions." His petition does not pinpoint particular instructions, but we assume his objection is aimed at the instructions involved in his direct appeal. Davis v. State, supra,440 S.W.2d at 248-49. The Arkansas Supreme Court found that instructions on burden of proof and intent were given in accordance with the evidence in the case and the law of Arkansas. Id. In view of this finding and in view of appellant's scant presentation of his claim in this habeas corpus proceeding,4 we see no error so fundamental as to raise a cognizable due process issue. As a general rule, improper jury instructions are not a basis for habeas corpus relief. Cooper v. Campbell, supra, 597 F.2d at 631, Citing DeBerry v. Wolff, 513 F.2d 1336, 1338-39 (8th Cir. 1975); Spratlin v. Solem, 577 F.2d 56, 60 (8th Cir. 1976). Cf. United States ex rel. Matthews v. Johnson, 503 F.2d 339 (3d Cir. 1974) (en banc), Cert. denied sub nom. Cuyler v. Matthews, 420 U.S. 952, 95 S. Ct. 1336, 43 L. Ed. 2d 430 (1975) (refusal of trial court to give requested instruction on voluntary manslaughter was denial of due process).

A closer claim, and one which rises to constitutional dimensions, is that evidence of insanity outweighed evidence of competency and, therefore, that appellant's conviction rests on insufficient evidence. The Arkansas Supreme Court rejected this contention, holding that "there was testimony from which the jury could have found either way." Davis v. State, supra, 440 S.W.2d at 248.

Our view of this claim is controlled by the Supreme Court's recent decision in Jackson v. Virginia, --- U.S. ----, 99 S. Ct. 2781, 61 L. Ed. 2d 560 (1979). The Court held that sufficiency of the evidence supporting conviction is cognizable as a federal constitutional claim under 28 U.S.C. § 2254. Id. 99 S.Ct. at 2790. Habeas corpus relief is warranted if the record shows that no rational trier of fact could have found proof of guilt beyond a reasonable doubt.5 Id. at 2792.

It is not dispositive that the Arkansas Supreme Court found sufficient evidence to support the jury's verdict. Under Jackson v. Virginia, the decision of the state court is not conclusive and does not bar a claim under § 2254, Id. at 2791, although the fact that the state court invoked the proper standard entitles its decision to great weight. Id. at 2791 n. 15. State proceedings cannot be presumed to be without error in the constitutional sense. Id. at 2791. The question on this appeal, therefore, is whether no rational trier of fact could have found appellant guilty beyond a reasonable doubt. Id. at 2792.

The record reveals testimony by two doctors that appellant was insane, and testimony by two doctors that he was mentally competent. Applying the Jackson standard to this evidence, we find no basis for habeas corpus relief. There is ample basis in the state transcript for a finding of sanity where, as here, the evidence is equally balanced and the testimony of those who testified that appellant was sane is worthy of belief. We note that on slimmer evidence, consisting merely of lay testimony, the Supreme Court has upheld a finding of sanity under the Jackson standard. Moore v. Duckworth, --- U.S. ----, 99 S. Ct. 3088, 61 L. Ed. 2d 865 (1979).

With the aid of retained counsel,6 appellant raised three additional claims in district court. These are the allegation of sixth amendment violation in the lack of a competency hearing immediately before trial, the claim of fifth and sixth amendment violation in an examination by state psychiatrist Dr. Charles Yohe, and the claim of denial of due process and sixth amendment rights in several In camera hearings. None of these claims was raised on direct appeal,7 and none has been the subject of state post-conviction proceedings.8

Exhaustion of state remedies is an express requirement of federal habeas corpus relief under 28 U.S.C. § 2254(b).9 Even though the state has not argued non-exhaustion in the present case, we defer to the statutory requirement out of respect for state-federal comity, raising the issue of exhaustion Sua sponte. Conner v. Auger, 595 F.2d 407, 413 (8th Cir. 1979); Blackwell v. Wolff, 454 F.2d 48, 50 (8th Cir. 1972); Johnson v. Bennett, 386 F.2d 677, 678 (8th Cir. 1967), Vacated on other grounds, 393 U.S. 253, 89 S. Ct. 436, 21 L. Ed. 2d 415 (1968).

In the present case, the state erroneously conceded in its district court pleadings that state remedies were exhausted. This fact could be viewed as a waiver of the exhaustion requirement. However, we find no precedent recognizing inadvertent waiver of exhaustion, and we accordingly decline to recognize the state's error as an express waiver.10

Appellant has raised one final allegation which cannot be recognized, both because it is unexhausted as to state remedies and because it is raised for the first time on appeal. Young v. Arkansas, 533 F.2d 1079, 1080 (8th Cir. 1976). This claim, that the arresting officer failed to issue Miranda warnings, can properly be raised in Arkansas post-conviction proceedings along with other unexhausted claims.

Judgment is reversed and remanded as to the issues of a pre-trial competency hearing, examination by Dr. Yohe, appellant's absence from chamber conferences, and lack of Miranda warnings, with directions to dismiss the petition on the ground that petitioner failed to exhaust his state remedies. Judgment is affirmed as to the claims of improper jury selection, the admissibility of photographic evidence, erroneous jury instructions, and the sufficiency of the evidence of sanity.