JACKSONVILLE, Fla. — A Jacksonville man learned he will be in prison until his late 90s Thursday after he pleaded guilty to the murder of his girlfriend in October, according to court records obtained by First Coast News.

According to court records, 46-year-old Jason Mieczkowski pleaded guilty to second-degree murder in the death of his girlfriend, 61-year-old Lois Nelson, in October, 2024.

He received a 50-year prison sentence, with credit for more than half a year of time served. 

patrol officers responded to the 2800 block of Bulls Bay Highway at about 4:30 a.m. Thursday, October 9, in reference to a woman who was unresponsive.

The woman now identified as Nelson was found with “an apparent head injury,” and was pronounced dead at the scene, police said.

Nearly 13 hours later, at 5:29 p.m. Thursday, Mieczkowski was arrested for Nelson’s murder, his arrest report shows.

The report states that the murder is domestic violence-related and that officers found Nelson “partially naked, with bruising to her face and body” when they arrived at the scene. Furthermore, the report says Nelson “sustained several traumatic injuries, which were estimated to have happened within minutes to hours of the time of discovery and death.” The Medical Examiner’s Office then ruled that the homicide was caused by blunt force trauma, according to the report.

Mieczkowski “could not provide consistent information for a basic timeline of events,” the report also mentions. The part of the report that mentions specific information as to what led to Mieczkowski being charged is redacted. He had been the subject of battery in two prior incidents, one in which he punched a former girlfriend in the face after an argument over finances resulted in a broken jaw, according to JSO.

Mieczkowski was also charged with violation of probation or community control, jail records indicate