A murder charge brought against a Prince George's County man in the strangling death of a 22-year old woman last October was dropped this week after a statement the man made to police implicating himself in the slaying was ruled inadmissible in court.

A Prince George's County circuit court judge ruled Thursday that the state's attorney's office could not use a statement made by Francis Burroughs, who was charged in the death of his next door neighbor, Mariann Katherine Lorenz, a University of Maryland graduate student.

After being strangled Lorenz was flung from the fourth floor balcony of her Adelphi apartment. Police initially questioned Burroughs as a witness, and the judge ruled that a statement he made later as a suspect had to be suppressed because police had not read him his rights soon enough.

"It's tragic," said prosecutor Michael Whalen. "Our whole case was based on that confession. We disagree with the ruling, but we have no avenue to appeal."

Prosecutors can bring charges again only if they develop new evidence.

Whalen said police first brought Burroughs, a 27-year-old Metro employe, to headquarters for questioning as a witness because he had called police to report the murder.

Later police questioned a woman who said she lived beneath Burrough's apartment and had heard screams and struggling sounds. That led police to believe Burroughs might have been involved. They then advised him for the first time of his right to remain silent or obtain an attorney, and Burroughs made a statement implicating himself.

But in his ruling, Judge Albert Blackwell said that when police first took Burroughs to the station for questioning, the interrogation-like atmosphere there required that they read him his rights before even questioning him as a witness. Because they did not, Burrough's statement was ordered suppressed.

The defense had contended that police suspected Burroughs of the crime all along.

According to Lisa Ann Oristian, the slain girl's roommate, Lorenz was from Ohio, and had attended the University of Maryland for about five weeks before she was murdered. She was "friendly, outgoing and intelligent," Oristian said. The last time she saw her roommate, Oristian said, was Oct. 3, the day of the murder, when Lorenz left her to meet a friend to play racketball.

Police said they later found Lorenz's partly clad body in bushes next to her apartment building. She had been strangled with a cord or some object, and thrown four floors to the ground, they said.

Burroughs could not be reached for comment yesterday, but his attorney, Ben Wolman, said Blackwell," should be complimented for having the courage to call it as he saw it."

"Burroughs told me as we walked out of court that he was glad it was over and he appreciated the consideration the judge had given him," Wolman said.