In an unexpected turn of events, a routine welfare check in Oklahoma last week led to a breakthrough in a murder cold case dating back to 2016.

Joseph Beck, found sitting alone on the side of an interstate highway outside of Oklahoma City, voluntarily confessed to the murder of 19-year-old Jennifer Kyli Molloy, according to authorities.

The confession was made to a state trooper who was performing the welfare check. The trooper had been alerted by a passerby who reported seeing a solitary man near an exit off I-40, as stated by the Oklahoma Highway Patrol. Following the confession, Beck was taken to the Edmond Police Department, which had been responsible for the initial investigation into Molloy's murder. The 28-year-old was subsequently arrested as a suspect in her death and charged with first-degree murder. Records indicate that Beck was booked into the Oklahoma County Detention Center on Friday and remained there as of Monday morning.

The Oklahoma Highway Patrol expressed their hope that this development would provide much-needed answers for Molloy's family.

Molloy's lifeless body was discovered in her apartment in Edmond, approximately 15 miles north of Oklahoma City, on October 5, 2016. The Edmond Police Department described her death as "suspicious." Despite several leads over the years, no arrests had been made in connection with her death until now.

MUST WATCH NY DEPUTY COMMISSIONER: "SOMEBODY IS RADICALIZING OUR STUDENTS"

According to CBS affiliate KWTV, Beck confessed to strangling Molloy to death. The Edmond police stated that Beck became their primary suspect in the previously cold case after he divulged specific details about the murder. During an interview with investigators, Beck revealed that he and Molloy were co-workers and admitted to having been attracted to her. He recounted visiting Molloy's apartment with the intention to assault her and feeling anger when she asked him to leave. It was then, he confessed, that he killed her.

WATCH: FLORIDA TO ELIMINATE WOKE TRAINING INDOCTRINATION

The victim's father, Johnny Molloy, expressed shock and anger upon learning of Beck's confession to KWTV. However, he also acknowledged that the arrest brought some closure. "I've been waiting on this for a long, long time and I never really thought it would happen," he said. The exact nature of the relationship between Beck and Kyli Molloy outside of work remains unclear, but her family revealed that they had known the suspect for some time.

ISRAEL PUSHES AHEAD WITH RAFAH OPERATION, INITIATES EVACUATION OF PALESTINIANS

Christa Stanfiel, the victim's sister, told KWTV, "Growing up with Joseph, he was the nicest guy, he was the sweetest guy. You would never think anything ill-mannered from him and to know this happened and that he did this over something so stupid."

BIDEN'S ECONOMIC POLICIES ARE CRUSHING THE AMERICAN DREAM

Stanfiel also revealed that Beck had reached out to her several months after her sister's death, expressing a desire to meet. He continued to contact her until as recently as April of this year, but she never responded to his messages. The Edmond Police Department was contacted by CBS News for additional information but has not yet responded.

Emily Mae Czachor, a reporter and news editor at CBSNews.com, covers breaking news, often focusing on crime and extreme weather. She has previously written for outlets including the Los Angeles Times, BuzzFeed, and Newsweek.