A man convicted of manslaughter and another found guilty of rape are entitled to new trials because Prince George's police detectives violated their rights in obtaining their videotaped statements, two Maryland appellate courts have ruled since last week.

The decisions, from the Maryland Court of Appeals and the state's Court of Special Appeals, mean that at least four videotaped statements by suspects accused of violent crimes have been suppressed since June because of actions by Prince George's police detectives.

Prince George's police began videotaping statements in homicide and other major investigations in 2000, after a Washington Post series that documented false confessions in murder cases.

On Tuesday, the Court of Special Appeals overturned the Sept. 12, 2003, conviction of Terrence Saunders, now 40.

A Prince George's jury convicted Saunders of voluntary manslaughter and a handgun violation in the March 27, 2003, fatal shooting of Rernoldo B. Slyke, 47.

According to the appellate opinion and other court records, Saunders told police that he shot the victim as Slyke was trying to break into his Temple Hills home. Saunders opened a door and shot Slyke as Slyke tried to run away, according to a police charging document by homicide Detective Robert Frankenfield.

About 90 minutes after the shooting, Frankenfield conducted a videotaped interview of Saunders. After he was read his rights to remain silent and to have an attorney, Saunders asked for a lawyer, the appellate court wrote. According to a partial transcript of the interview, Frankenfield continued to ask whether Saunders would like to talk to him; Saunders asked for an attorney four more times.

Frankenfield left Saunders alone for about 90 minutes. When he returned, he resumed asking Saunders what happened. Saunders, without revoking his request for an attorney, gave Frankenfield his account of the shooting, the appellate court wrote.

The appeals court ruled that Circuit Court Judge E. Allen Shepherd should have granted a defense motion to suppress the statement because Frankenfield, not Saunders, renewed the discussion of the shooting.

On Aug. 10, the state Court of Appeals threw out the second-degree rape and second-degree assault conviction of Shanquon K. Taylor, who turned 23 yesterday.

Circuit Court Judge Richard H. Sothoron Jr. convicted Taylor of assaulting a young woman in his Forestville apartment June 1, 2002.

In a videotaped interview, Prince George's Detective Jeffrey Schreiber told Taylor that if he was forthright and "you're pretty truthful to me, I can always make a recommendation to the commissioner" who would determine whether Taylor was jailed. Taylor then made a statement.

The appellate court wrote that Sothoron should have suppressed the statement. Police are not allowed to make promises or threats to obtain a statement, legal experts said.

Two other statements by defendants have been suppressed since June by Prince George's Circuit Court judges. In both cases, judges found that the statements were improperly obtained.

Sharon Taylor, a spokeswoman for Police Chief Melvin C. High, said yesterday that High believes that "the fact a court suppressed a statement does not necessarily mean our detectives did anything wrong."

Taylor said Maj. Vincent Gay, head of the criminal investigations division, and one of his subordinates review the performance of detectives in major cases to determine whether there is a need for adjustment in "tactics, policy, training or personnel."

So many suppressed statements might indicate a fundamental problem in the training or culture of Prince George's police investigators, a legal expert said.

"If suspects assert their rights to an attorney and it's repeatedly ignored, it suggests not only a lack of training, but a lack of commitment to the Fifth Amendment," the right against self-incrimination, said Michael Pinard, an assistant professor at the University of Maryland School of Law.

Pinard and other legal experts said the U.S. Supreme Court has made it clear that law enforcement officers must stop interrogating a suspect the moment the suspect asks for an attorney. An interrogation can resume only if the suspect, without prodding by an investigator, states clearly that he no longer wants an attorney, legal experts said.