March 23 (Reuters) - Videotapes of nine hours of interrogation in which police lied to and threatened an upstate New York man accused of killing his infant son show his confession was not coerced, a state appeals court has ruled.

Adrian Thomas of Troy was sentenced to 25 years to life in prison after being convicted in 2009 of murdering his four-month-old son by repeatedly throwing him on a bed.

In upholding the conviction, the Appellate Division, Third Department, rejected Thomas' claim that investigators used "false promises, misrepresentations and threats" during nine hours of interrogation that took place over two days.

"Upon our review of the unredacted recorded interviews...we find that (Thomas) voluntarily confessed during noncustodial interviews in which police employed permissible strategies aimed at eliciting the truth," Justice Edward Spain wrote for the court in a ruling released Thursday.

A documentary about the case debuts next weekend.

In September 2008, Thomas' wife discovered their son, Matthew, unconscious in his crib. When the boy, who had pneumonia, died two days later, doctors discovered severe swelling in his brain consistent with it moving back and forth inside the skull. They also found signs of sepsis, a potentially deadly infection that often accompanies pneumonia.

Thomas' six surviving children were soon removed from his home, and he voluntarily agreed to speak to police without a lawyer. He was questioned for two hours on the first day before suggesting he was suicidal, at which point he was taken to a hospital for observation.

Spain wrote that the 15-hour hospitalization gave Thomas ample opportunity to relax, sleep and consider whether to consult with an attorney.

'TINY, HELPLESS INFANT'

The next day, Thomas was questioned by police for seven hours, during which time he was offered food, drinks, bathroom breaks and cigarettes.

He first signed a statement admitting he had accidentally hit Matthew's head on his crib a number of times.

Several hours later, the 500-pound Thomas confessed to violently throwing the boy onto a bed three times in the four days prior to his hospitalization.

The Thomas case was the first in Rensselaer County in which jurors were able to view an entire interrogation and confession.

At trial, Thomas argued among other things that police had repeatedly lied, mainly by telling him that a confession could save Matthew's life even though police already knew the boy would not survive. They also threatened to arrest his wife for Matthew's death.

The jury convicted Thomas of depraved indifference murder and sentenced him to 25 years to life.

On appeal, Thomas maintained that the police used illegal tactics to obtain a false confession.

But the Third Department found that investigators' conduct was appropriate, particularly because Thomas was treated well and had the option of stopping the interview at any time prior to his confession.

Troy Police Sgt. Adam Mason, who conducted most of the interrogation and secured the confession, was "calm, often friendly and supportive" throughout the interview, according to Spain and the other Third Department justices who watched the trial.

"The recorded interviews simply do not support the conclusion that defendant was unduly fatigued or sleepy, or that he was physically or psychologically overwhelmed," Spain wrote.

The court also dismissed Thomas' argument that the murder did not rise to the level of depraved indifference.

"His acts, born of anger and frustration, against a tiny, helpless infant...reflected 'wanton cruelty, brutality or callousness directed against a particularly vulnerable victim,'" Spain wrote.

Justices John Lahtinen, Bernard Malone, Leslie Stein and John Egan rounded out the panel.

Thursday's ruling comes as a number of officials, including Chief Judge Jonathan Lippman, the state Bar Association and some state lawmakers, are calling for legislation mandating the recording of custodial interrogations. In Thomas' case, the interview was noncustodial until he signed the confession shortly before the interrogation ended.

Rensselaer County District Attorney Richard McNally said in an interview that while most advocates of mandatory videotaping suggest it would be a deterrent to police misconduct, the Thomas case shows that recordings can vindicate police when a confession is called into question.

"There would have been a different result if (the interrogation) had not been videotaped," he said of the Thomas case. "But we don't need the legislature to tell us to do it; let juries tell us."

Thomas' attorney, Jerome Frost, did not return a call seeking comment.

The Thomas case spurred two Los Angeles filmmakers, Blue Hadaegh and Grover Babcock, last year to create "Scenes of a Crime," a full-length documentary about the case that includes footage of the interrogation and interviews with those involved. The film will be screened at New York City's Cinema Village for one week beginning March 30.

The case is the People v. Adrian Thomas, New York State Supreme Court, Appellate Division, Third Department, No. 513464.

For Thomas: Jerome Frost

For the prosecution: Rensselaer County Assistant District Attorney Gordon Eddy

(Reporting by Dan Wiessner)

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