A day after Peter Robinson testified in his murder trial in Bangor, his wife took the stand.The 49-year-old Bradford man is on trial for the beating death of 71-year-old David Trask of Hudson.On Friday morning, the defense had Cheryl Robinson recount many of the land disputes she witnessed between her husband and the Trask family.Similar to her husband’s testimony, Cheryl Robinson told the jury threats made by certain Trask family members to her husband made her extremely nervous. Because of these, Cheryl Robinson told the courtroom she was looking into moving. She said, “I knew there would be problems the whole time and it wasn’t worth it.”She even said she purchased her own hand gun in 2011, fearing for her and her husbands lives.The defense also had Cheryl Robinson recount how she found her husband after he killed David Trask.Tearfully, she said that her husband had burst through the door and was down on his knees crying.She testified that he said something about Trask coming at him with a crowbar. He thought Trask was going to kill him, so Robinson hit him really hard.Trask was killed in November 2011. Robinson claims it was self defense.On Friday afternoon, after Cheryl Robinson’s testimony, the defense had Executive Director of the Police Policy Studies Council to take the stand.The witness stated that he had extensively researched police officers’ degree of error when responding to an incident that was more life threatening than normal. He testified that “a major factor” regarding “questionable shootings” in the field occurred when the officers’ opponents reached to his or her waist bands with their dominant hand.The defense hoped this testimony would reinforce the defendant’s self defense claim. The trial will continue Monday.The defense would like three of the victim’s relatives to take the stand to testify about an alleged plot to kill Robinson after Trask’s death.The judge hasn’t decided if that testimony will be allowed.The three relatives have indicated they will refuse to answer if called to the stand.