How a small piece of a bathroom door lock helped solve a nurse's murder

In nan early greeting hours of Dec. 16, 2022, St. Paul, Minnesota, homicide detectives Abby DeSanto and Jennifer O'Donnell were called to a downtown flat building to analyse a reported suicide. A 32-year-old female named Alexandra Pennig had been recovered dormant successful her bath pinch a azygous gunshot coiled to nan head.

For nan detectives, what really happened to Pennig is thing that still haunts them to this day. And it's nan mobility astatine nan halfway of "The Strange Shooting of Alex Pennig," reported by "48 Hours" contributor Natalie Morales airing Saturday, Oct. 26 astatine 10/9c connected CBS and streaming connected Paramount+.

Matthew Ecker, left, and Alex Pennig Terri Randall/Mary Jo Pennig

When detectives DeSanto and O'Donnell arrived astatine nan apartment, they recovered retired Pennig had not been unsocial astatine nan clip of her death. A man named Matthew Ecker was besides there. Ecker and Pennig were some nurses and had met 2 years earlier erstwhile they worked astatine nan aforesaid clinic. Ecker told first responders nan weapon was his, and that Pennig had grabbed it, locked herself successful nan bathroom, and past fired nan shot. "I thought everything was fine," he said. "And past she conscionable grabbed nan gun." Ecker told first responders that aft he heard nan changeable he instantly collapsed unfastened nan bath door: "I tried to do what I could. And past I washed my hands … That's why I don't person thing connected my hands." Ecker said he past called 911. But it was excessively late. He said he didn't cognize why Pennig would do this.

In Pennig's apartment, location was intoxicant and six bottles of medicine medication, including antidepressants, each prescribed to Pennig. For nan detectives, it suggested Alex mightiness person been depressed, and they wondered if Ecker's communicative that she took her ain life was true.

But they besides noticed thing that seemed to contradict Ecker's story. He had said he washed his hands successful nan bath descend earlier calling 911, but DeSanto recalled nan first responders told her nan descend was dry. "The descend was dry. If he had said, you know, he called nan constabulary correct away, that descend astir apt would've been still wet," DeSanto explained, "but it was very barren successful there."

When O'Donnell looked into Pennig's background, she learned from Alex's parents that Alex had struggled successful nan past pinch slump and addiction. "I had asked, um, if she had been suicidal successful nan past, um, and dada said, she had, um, tried, uh, to overdose before," said O'Donnell. According to Alex's father, Jim Pennig, respective years prior, Alex had taken a fistful of pills "and past had told her mom that she was attempting suicide." After that, Alex's parents told nan detectives they sent her to rehab, and she yet sewage clean. Despite her past struggles, Alex's parents told O'Donnell they had conscionable seen her astatine Thanksgiving. And her mom, Mary Jo Pennig, had conscionable talked to her that evening. "She was doing well," she said. For them, nan thought that their girl had died by termination did not make sense. "Knowing your kid, it didn't fit," Mary Jo Pennig said.

Since Ecker was nan past personification to spot Alex Pennig alive, nan detectives zeroed successful connected him. "He's nan only 1 that tin show america what happened. He was nan only 1 that was there," said O'Donnell. They questioned Ecker astir what had happened that night. He said he and Alex Pennig had gone retired to respective section bars, and erstwhile they arrived backmost astatine her place, everything was fine: "We were laughing connected nan measurement home," said Ecker. DeSanto asked him if, erstwhile they sewage into nan apartment, they had gotten into a fight. Ecker said they did not.

DET. ABBY DESANTO: You guys weren't arguing aliases anything?

MATTHEW ECKER: No.

DET. ABBY DESANTO: There's nary conflict pinch you two?

MATTHEW ECKER: Not betwixt us. 

For hours, Ecker continued to opportunity Pennig had locked herself successful nan bathroom, fired nan changeable and past he collapsed unfastened nan doorway to effort and thief her: "That weapon went disconnected down a closed doorway … I did not sprout her."

This mini portion of metallic from a bath doorway fastener was recovered nether Alex Pennig's body. Ramsey County District Court

But nan detectives had their doubts. Then they sewage a telephone from nan forensic portion that was still processing nan scene. And according to O'Donnell, what they recovered changed everything. "Once Alex was moved, they recovered underneath wherever Alex had been laying was a information metallic piece," she said. "It was nan style of a ring, and astir nan size of a quarter." O'Donnell said it was portion of nan fastener from nan bath door, and nan truth that it had been discovered nether Pennig was key. "For us, it meant that nan doorway was forced unfastened earlier she was shot."

The detectives felt nan find of nan metallic ringing proved Ecker had lied and had not surgery nan doorway unfastened aft he heard nan shot. The detectives suspected Pennig and Ecker had based on and that she had locked nan bath doorway to get distant from him. Then Ecker collapsed unfastened nan door, nan metallic portion collapsed disconnected and fell to nan ground, and past he changeable Pennig and she landed connected apical of it.

Ecker was charged pinch second-degree murder. In February 2024 he was convicted and later sentenced to 30 years. He is appealing his conviction.

In:
• 48 Hours
• Minnesota
• Murder