Nancy Kerrigan's Brother: I Was Too Drunk to Waive My Rights

Updated at 2:27 p.m. ET

WOBURN, Mass. - Lawyers for the brother of figure skater Nancy Kerrigan are asking a judge to toss out any statements he made to police about the death of his father, claiming that Kerrigan was too drunk to voluntarily waive his right to remain silent.

Mark Kerrigan is charged with manslaughter in the 2010 death of his 70-year-old father.

Prosecutors say Daniel Kerrigan died after a fight with his son. Kerrigan's lawyer and family say Daniel Kerrigan had a heart condition and his son was not responsible for his death.

Kerrigan's lawyers argue in a motion to be heard Thursday that he did not voluntarily waive his right to remain silent due to "severe intoxication."

Police have said Kerrigan told them he grabbed his father by the throat and pushed him, and then his father slumped to the floor.

Earlier Monday, Kerrigan was sent to jail after failing required alcohol screenings while awaiting trial.

Kerrigan had been free on $25,000 bail after his arraignment last year. A judge revoked Kerrigan's bail Monday after prosecutors said he failed four breath tests in a half-hour period Saturday night.

The readings, which ranged from .025 to .036, were below the legal driving limit of .08. Assistant District Attorney Elizabeth Keeley said the readings — taken at Kerrigan's Stoneham home — violate the conditions of Kerrigan's bail, which included that he not drink any alcohol and that he be given random drug and alcohol screenings.

"It's a very serious violation in light of this case and the circumstances," Keeley said during a hearing in Woburn Superior Court.

Kerrigan's lawyer, Janice Bassil, said Kerrigan told her that he had taken cough syrup because he has a bad cold.

"He informed me that he had taken a bunch of cough syrup," she said.

Bassil argued that over-the-counter cough syrup can have a high alcohol content and asked Judge Joseph Walker to allow Kerrigan to remain free on bail.

"He has been compliant with all of the conditions set for him by probation," she said.

Bassil told the judge she plans to try to retrieve the bottle of cough syrup from Kerrigan's house, have it tested for alcohol content and ask Kerrigan's mother to submit an affidavit to verify that Kerrigan did drink the medicine.

The judge said he may be willing to revisit the bail issue if the defense is able to show that Kerrigan had taken only medicine.