Follow CBSDFW.COM: Facebook | Twitter

IDAHO FALLS, Idaho (CBSDFW.COM/AP) — A 39-year-old man from Jackson, Wyoming, is charged with killing his pregnant girlfriend at her cabin near Driggs, Idaho.

Erik Martin Ohlson was charged Wednesday with two counts of first-degree murder in the deaths of 39-year-old Jennifer Nalley and her unborn child. He did not enter a plea and is being held without bond. His preliminary hearing is set for July 20 in Teton County, Idaho.

Ohlson was charged Tuesday with driving under the influence after crashing into a tree about 3 miles from Nalley’s home at about 1:30 a.m. Tuesday. He had just appeared in court on the DUI when a relative found Nalley’s body.

An autopsy found she was shot several times by a .45-caliber handgun.

Nalley had a physics degree and was a founding member of the Texas Rollergirls roller derby league. Her roller derby name was “Pixie Tourette.”

The organization expressed their grief in a Facebook post to remind of the perils of domestic violence.

(©2016 CBS Local Media, a division of CBS Radio Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)