A New Hampshire man, aged 38, has been sentenced to a lengthy prison term following the murder of his ex-girlfriend while their 4-year-old daughter was in close proximity.

Dustin Mark Duren was sentenced last week to between 45 years and life behind bars for killing 31-year-old Caitlyn Naffziger. A jury in October convicted him of second-degree murder, reckless conduct with a deadly weapon and endangering the welfare of a child.

According to prosecutors, the man, identified as Duren, and his ex-girlfriend, Naffziger, were embroiled in a bitter custody battle over their two young children, aged 4 and 1. In January 2024, Duren relocated from Minnesota to New Hampshire, taking one child with him. Shortly thereafter, on February 27, 2024, Naffziger traveled from Minnesota to New Hampshire with the other child.

The couple, along with their children, were at Duren’s apartment in Berlin, New Hampshire. Tensions were high, as Duren repeatedly inquired about when Naffziger would leave, expressing his desire for her to go.

In a sentencing memorandum, prosecutors detailed that Naffziger either ignored Duren’s requests or failed to provide a satisfactory response, which led to his growing frustration and eventual anger.

The situation escalated on February 29, 2024, when Duren attempted to forcibly remove Naffziger from his apartment, intending to keep the children there. She resisted, holding the 4-year-old while seated on a couch under a pink unicorn blanket. Duren then forcibly pulled the child away and fatally shot Naffziger in the head. Given his background as an ex-Marine and expert marksman, prosecutors asserted that Duren was fully aware of his actions when he pulled the trigger.

Following the tragic incident, the young girl recounted to a doctor that the sound of the gunshot had hurt her ears.

“Mommy and daddy were fighting,” she told the doctor. “Daddy hurt me and mommy. Mommy had lots of blood.”

After shooting the victim, Duren grabbed the kids and took off, which sparked an Amber Alert. Witnesses said they saw Duren and the kids in the parking lot of an Applebee’s. The children were unharmed.

Duren testified during the trial, claiming he felt as if his ex was going to kidnap the children. But the jury didn’t buy his argument and convicted him after deliberating for roughly five hours.

At Duren’s sentencing hearing, Naffziger’s aunt Shannon Spurgeon spoke about the impact the murder has had on her loved ones.

“Nothing can prepare you for the heartbreak of losing someone like Caitlin,” Spurgeon said. “Losing her in such a violent and senseless way shattered everyone who loves her.”

The victim’s stepfather Tim Smith said the murder “culminated years of classic textbook domestic violence” such as isolating her from her family and controlling her.

“When the control that Dustin imposed on Caitlyn, which was facilitated by using their children as pawns, was lost, he knew he had lost control, because Caitlyn told him so,” Smith said. “Like so many abusers, Dustin resorted to murder in a vicious attempt to maintain that control at all cost.”