Alexandra Pennig and Matthew Ecker

Minnesota Nurse Practitioner Convicted of Murdering Mistress After Claiming She Shot Herself

A Minnesota man who claimed his mistress fatally shot herself has been convicted of her murder, the Pioneer Press reports.

On Friday, a jury found 45-year-old Matthew Ecker guilty of second-degree intentional murder of 32-year-old Alexandra Pennig.

The case stems from the early morning hours of December 16, 2022, when Ecker called 911 claiming that Penning had committed suicide in her downtown St. Paul apartment.

Married and a father at the time of the shooting, Ecker was having an extramarital affair with Pennig.

In an interview with police, Ecker alleged that Pennig shot herself in the head. He told investigators she took his gun out of his backpack, ran into a bathroom, locked the door, and then shot herself.

After he heard the gunfire, Ecker said he rushed to the bathroom and pushed the door open to find Pennig on the floor in a pool of blood.

Officers responded to the 911 call and noticed inconsistencies and suspicious behavior early on.

After the shooting, Ecker allegedly took the pistol and put it in his suitcase because, he said, he was afraid he would get in trouble. The gun was his and he had a permit for it. But after seeing Pennig on the bathroom floor, he put the gun on her chest. Investigators also noted the apparent cleanliness of the gun, despite the nature of the scene.

Ecker said he tried to plug the bullet wound to slow blood loss, but his hands were clean when officers arrived. He claimed that he washed them using soap before he dialed 911, yet the bathroom sink was dry, according to authorities.

Further, Ecker initially claimed that Pennig was still breathing when he found her and that he tried to save her life. But he later said he did not perform CPR and did not know what to do, even though he worked as an emergency room nurse practitioner.

Investigators also noted that Pennig was right-handed, yet the gun was found in her left hand.

Records show Ecker was refilling prescription drugs for Pennig, a registered nurse, and helped cover her rent. Ecker and his family lived in Fergus Falls, about 200 miles northwest of Pennig’s St. Paul apartment.

Ecker’s attorney, Bruce Rivers, told jurors the state presented no physical evidence that his client shot Pennig. Rivers also said Pennig was dealing with depression and had attempted suicide previously.

“Two days prior, in text messages she wrote that she felt hopeless,” Rivers said in opening statements, according to KARE 11.

Pennig was dating another man and had gotten into a dispute with him the day prior, which Rivers said distressed Pennig.

Two medical examiners, including one hired by the defense, ruled the death as undetermined.

After the verdict was read, Ecker was taken into custody. He is scheduled to be sentenced on March 29.

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[Feature Photo: Alexandra Pennig/Facebook & Matthew Ecker/Ramsey County Sheriff’s Office]