Rudolf Knapp told police he acted in self-defense, while investigators pointed to messages, injuries and witness accounts.
LITTLE CHUTE, Wis. — An Appleton man accused of strangling his girlfriend during a late-night argument later sent messages calling himself “evil and sick,” police said, before telling investigators he had acted to protect himself.
Rudolf Knapp, 59, was charged in Outagamie County with attempted first-degree intentional homicide, strangulation, substantial battery and disorderly conduct after an incident at a Little Chute home. The case turns on sharply different accounts of the same bedroom struggle. The woman said Knapp got on top of her and choked her until she could not breathe or speak. Knapp said the woman had attacked him first, drugged him and left him with no choice. Police said the woman’s injuries, the 911 call, a child’s account and Knapp’s own later statements support the charges.
The messages came after police say Knapp left the home in a Mercedes-Benz before officers arrived. The woman allowed investigators to review her phone after she was treated at a hospital. According to the criminal complaint, Knapp sent multiple texts that went unanswered. One message said he had no idea how he lost control and described himself as “evil and sick.” Another thanked the woman for “one last good day.” Police said Knapp also made threats about taking his own life. Investigators spoke with one of his friends, who said Knapp had admitted to the assault and made suicidal comments. Officers then went to Knapp’s home, but he did not answer the door.
By the time police interviewed Knapp, he had gone to the Outagamie County Sheriff’s Office to report that he had been drugged and assaulted. He told officers the woman gave him hydroxyzine after they attended church on Easter and claimed she put Xanax in a soda. He also said she swung a box cutter or razor blade at him while yelling about the custody of her children. Knapp told police he “had no other option” but to strangle her because she was going to kill him. Investigators challenged that account, saying the cuts on Knapp’s body did not fit the struggle he described or the woman’s statement.
Police said Knapp made other statements that did not settle the question of intent but showed his account shifting during the interview. When asked whether he was trying to kill the woman, Knapp said no. “I just wanted her to stop hurting me. I was just so tired of being hurt by everybody,” he said, according to the complaint. He also discussed his mental health and called himself “a monster.” Police said he said he had never been a bad person and asked, “Who does that?” Investigators documented those statements alongside the messages and the witness accounts. The complaint does not say Knapp had a lawyer present during the interview.
The woman gave police a different sequence from her hospital bed. She said she and Knapp had been in bed eating gelato when they started arguing. She told investigators she did not remember what the argument was about. What she did remember, police said, was Knapp on top of her, his hands around the front of her neck. She said she could not breathe or speak and went in and out of consciousness. The woman told police she thought she was going to die. She had first declined medical treatment at the house, but a friend later took her to the hospital, where officers interviewed her in more detail.
The first officers at the residence saw injuries before they heard the full account. Police said the woman was holding a bag of frozen food to her right eye. She had a bloody mouth and red marks on her neck. She did not want to discuss the incident in front of her son, according to the complaint. The son had been the person who called for help. He told dispatchers his mother was screaming and said an unknown man was choking her. Dispatchers heard screaming in the background before the boy stopped answering questions. That call brought Fox Valley Metro police to the 1500 block of Vandenbroek Road at about 11:45 p.m. Sunday.
The boy later told police he heard a commotion from his mother’s bedroom before hearing her scream. He went to the bedroom and saw a man he did not know on top of her. The boy yelled at the man, asking who he was and what he was doing in the house. Police said that man was later identified as Knapp. The complaint says Knapp began putting on his coat and fled before officers arrived. That account is important to the case because it placed another person in the home during the alleged attack and gave police a near-immediate report before the later dispute over self-defense emerged.
The charges were filed after Knapp’s arrest, and he appeared in court April 7. A judge set a $500,000 cash bond. A preliminary hearing date was not immediately set in early reports. Prosecutors would use such a hearing to present enough evidence for the case to continue toward trial. The defense would have the chance to challenge whether the state has met that threshold. Knapp is presumed innocent unless convicted. The case file described the woman as having been released from the hospital after treatment, but authorities did not publicly identify her.
Lt. Mark Wery of the Fox Valley Metro Police Department said the agency treats violence reports as serious because they can cause physical and emotional harm and threaten the safety of families. Police have not publicly described a recovered weapon or released results from toxicology testing. They also have not said what prompted the argument. What they have described is a series of statements: a boy calling for help, a woman saying she was unable to breathe, texts sent after the incident and a suspect who later said he had been attacked.
For now, the case remained active in Outagamie County after Knapp’s initial appearance. The next court steps will determine how prosecutors present the complaint’s claims and how Knapp’s self-defense account is addressed in the felony proceedings.
Author note: Last updated April 29, 2026.