For the second time in three years, a Prince George's County jury yesterday convicted a young Bowie man of murdering a veterinarian and his wife in their Bladensburg animal hospital in 1999.

After a five-day trial, the jury deliberated for about 21/2 hours before convicting Robert Angel Perez, 22, of two counts of felony murder, armed robbery and related charges. Perez did not react visibly as the verdict was read in the Upper Marlboro courthouse. He will be sentenced Jan. 26.

Perez was convicted of killing Nirwan and Shashi Thapar, both 52. Each victim was shot several times, and Nirwan Thapar's throat was cut.

Perez was first convicted in April 2001. Defense attorneys appealed the conviction, saying that police violated Perez's rights by interrogating him over a period of 52 hours to obtain a series of incriminating statements. Court rules require that a suspect be brought before a commissioner "without unnecessary delay."

In February, the Maryland Court of Special Appeals threw out Perez's conviction.

The special appeals court ordered a new trial for Perez so that Circuit Court Judge Graydon S. McKee, the trial judge, could reconsider defense motions to suppress Perez's statements in light of rulings by the Court of Appeals. That court threw out convictions in three other Prince George's cases because police engaged in prolonged interrogations of suspects before presenting them to commissioners.

McKee decided to allow prosecutors to use Perez's statements in the retrial.

Perez testified, as he had in the first trial, that he had been manhandled and intimidated into making the incriminating statements. Homicide detectives testified they did not mistreat or intimidate him.

Thomas C. Mooney, Perez's attorney, argued that Perez's statements were coerced. Mooney attempted to present as evidence a false confession that detectives obtained in the Thapar case in January 2000, eight months before police arrested Perez.

In September 2001, Jack B. Johnson, who was state's attorney at the time, said detectives had kept the false confession secret from prosecutors for 19 months.

McKee denied a motion by Mooney to introduce evidence of the false confession.

A co-defendant, Thomas Jefferson Gordon III, was convicted of the murders for a second time in October 2003. Gordon was originally convicted in January 2002. McKee overturned the conviction and granted Gordon a new trial after defense attorneys presented evidence that detectives abused Gordon to obtain a confession.

A daughter of the victims, Namita Thapar, 32, praised police and prosecutors.

"Justice has been served, but we thought that the last time," she said after yesterday's verdict.