A District of Columbia police officer who reported his wife missing six weeks ago was charged with her murder yesterday after her body was found in a shallow grave in a rural, wooded area of Charles County, Md.

The arrest yesterday of Steven John Shalkowski, 31, a firearms instructor at the city's Police Training Academy and eight-year veteran of the force, followed a meandering search for his missing wife, Irene, 26, that had involved police departments in both Maryland and Virginia.

The search had begun sometime after Shalkowski, who lived in Takoma park in Prince George's County with his wife, called police to report her missing on Oct. 28. He calmly told an officer who came to his home that he had last seen her five days before in the District and that the two had been having running domestic arguments.

"He gave no indication to think that this was something other than a normal family feud," said County police Sgt. Robert Law, a spokesman for the Prince George's County Police Department.

The Prince George's police officer wrote up Irene Shalkowski as a missing person and her name was punched into a computer network with links to police departments throughout the country. There was no further investigation until nearly a month later.

On Nov. 21, the Prince George's County department got a call from officers of the sheriff's department in Winchester, Va. They said their computer had shown her missing in Prince George's county and they were calling to say that they had found her car and some personal effects in a wooded area off rte. 600 near Gainesboro, Va. about 100 miles west of Washington.

Authorities refused yesterday to say what personal articles of Mrs. Shalkowski were found there but, Prince George's County's Sgt. Law said, "The articles found were apparently ment to divert the investigation of the Virginia authorities who would never find her body."

According to one source, a farmer who reported that Mrs. Shalkowski's car had been abandoned on Nov. 21 also described another car he said he saw leaving the site that day.

Prince George's County detectives went to the Winchester location and assisted sheriff's deputies in combing the wooded area.They then returned to the Washington area and began interviewing relatives and friends of the couple.

They questioned Shalkowski extensively early yesterday.

Late in the morning Prince George's police officers went to Charles County where they found the body of Irene Shalkowski in an 18-inch-deep grave in a wooded area outside Waldorf, about 25 miles south of the couple's home.

She had been stabbed, and shot with a shotgun.

Authorities said the killing occured near where the body was found.

Officer Shalkowski was taken by Prince George's police to Charles County where he was arrested and charged with his wife's murder.

Law said a second District of Columbia police officer is under investigation in connection with the case. One law enforcement source said authorities are seeking to determine whether the officer may have helped bury the body. CAPTION: Picture, STEVEN JOHN SHALKOWSKI . . . reported his wife missing