MINNEAPOLIS — A 69-year-old Minneapolis man who thought he was saving another man’s life when he let him into his home was instead shot in the head and killed, according to the victim’s family and police reports.

Thomas Sonnenberg was home Friday when a young man knocked on his door and asked to come inside because people were chasing him and wanted to kill him. Sonnenberg let the man in and called 911, and then he was shot, Sonnenberg’s daughter, Raina Baldwin, said Saturday night.

“He didn’t have his guard up because he thought he was helping save someone’s life,” Baldwin told the St. Paul Pioneer Press. “He was helping a stranger. He never met this person before.”

Sonnenberg’s wife was in another room when the man entered the house. Another daughter, Rachel Sonnenberg Baufield, told the Star Tribune that their mother went to see what happened and saw her husband get shot.

The man then tried to leave, but he couldn’t because Sonnenberg had locked the deadbolts from the inside and the key was in Sonnenberg’s pocket. The man then assaulted Sonnenberg’s wife, Baufield said.

“He threw keys. He threw whatever he could find at her. And then he threw her around,” Baufield said. “He drug her upstairs to her bedroom with the gun to her forehead, placing the gun in the same spot on her head as where he’d shot my father, between his eyes.”

Police said they arrived to find Sonnenberg dead and the suspect still in the house. The 20-year-old man, who has prior convictions of assault and shooting at a public vehicle or facility, was arrested on probable cause murder. Police have not yet disclosed a motive.

“He helped everyone he could,” Baldwin said of her dad. “He donated to charities all the time even though he hardly had any money himself. He had a good heart.”

Sonnenberg’s wife was recovering from her injuries at a family member’s home.