Confusing and contradictory testimony fueled a heated courtroom in the murder trial of an Elmira man. Marland Brooks, 39, is accused of stabbing Clark Van Etten to death in his Corning apartment last June. Brooks' girlfriend resumed her testimony in Steuben County Court Friday. Our Lara Greenberg has more.

STEUBEN COUNTY, N.Y. -- Conflicting testimony consumed most of day in Steuben County Court Friday as Samantha Smith continued to testify against her boyfriend and alleged murderer Marland Brooks.

Brooks is accused of stabbing Clark Van Etten to death over drugs and money in his Corning apartment last June.

Brooks' attorney entered into evidence a letter that Samantha Smith wrote to Marland Brooks while the two of them were in jail. In the letter, she mentions a knife and finally admitted on the stand to there being a knife at the scene of the incident. But she says both men were reaching for it, Marland Brooks ultimately grabbed it and she never saw that knife enter Clark Van Etten's body. But she later denied seeing the knife once again.

Smith testified that in another letter between the two, Brooks told her to say yes to every question his lawyer asked her in court. But she then testified that the letter just said to tell the truth.

"There were letters communicated back and forth. And I had the opportunity to review some of those letters and they were very beneficial to use for impeachment purposes," said Brooks' attorney David Morabito.

"She is a difficult witness. As she testified, she's had a long history of drug abuse, not a lifestyle that any of us would certainly encourage or want to engage in so it doesn't surprise me terribly," said Steuben County District Attorney Brooks Baker.

Smith also admitted to having sexual relations with men, including Van Etten, in exchange for money and drugs.

Two other witnesses took the stand Friday.

Brooks’ attorney says this killing was an act of self-defense.

Testimony continues Monday.

Brooks is charged with two counts of murder, robbery and criminal possession of a weapon.

Smith was originally charged with murder. She later accepted a plea deal, in which she'll spend 10 years in jail for robbery in exchange for an honest testimony against Brooks.