Son Allegedly Kills Mother, Wounds Father

STEVENSON RANCH — A 24-year-old man who became enraged when his mother confronted him about his excessive drinking stabbed her to death and then wounded his father early Sunday morning, a Los Angeles County Sheriff’s Department spokesman said.

Michael Tonnessen, who barricaded himself in the family’s home in the 25900 block of Coleridge Place for more than four hours following the stabbings, was arrested after a Sheriff’s Department SWAT team fired tear gas into the house, forcing him to surrender about 4:30 a.m., said Deputy Bob Killeen, a department spokesman.

Killeen said the incident began when Michael Tonnessen arrived home intoxicated and his mother, Theresa, confronted him. They heatedly argued inside the home and eventually went outside, he said.

When sheriff’s deputies arrived at the Tonnessens’ home shortly after midnight, much of the grisly scene had played out in front of the Tonnessens’ neighbors.

“I thought it was three kids fighting out in front of their home,” said Pam Vogt, who lives nearby. “They were struggling and I thought it was two guys beating on a girl until one of them shouted, ‘He just stabbed me and my wife.’ ”

Dan Deffenbaugh, another neighbor, said he ran out of his home when he heard screaming, and saw Theresa Tonnessen sitting on the ground with her arms wrapped around her midsection. Her husband, Kurt, was covered with blood and was screaming for help while trying to care for her, Deffenbaugh said. Meanwhile, Michael Tonnessen stood nearby and appeared to be celebrating, he said.

“[Michael] was pumping his fists in the air like he had just won a prizefight,” said Deffenbaugh. “We didn’t really understand what was going on until [Kurt Tonnessen] started yelling, ‘My son just stabbed me and my wife. Call the police.’ ”

Theresa Tonnessen, 51, suffered several stab wounds and was pronounced dead later at Henry Mayo Newhall Hospital in Santa Clarita, Killeen said. Kurt Tonnessen, 53, an engineer who was part of a crew that won an Emmy in 1996 for “The Tonight Show,” was listed in serious but stable condition with a single stab wound to his upper body, Killeen said.

Authorities said Michael Tonnessen was being held on $1-million bail at the Santa Clarita sheriff’s station on suspicion of murder and attempted murder. He is expected to be arraigned this week in Newhall Municipal Court, they said.

A weapon possibly used in the stabbings was recovered at the scene, authorities said.

Several neighbors said they could not remember any previous disturbances at the Tonnessen home, and were shocked by the incident.

Debbie Walsh, who lives two houses away from the family, said Theresa Tonnessen will be missed.

“She was the sweetest woman on the block,” Walsh said.