A Pennsylvania man who brutally murdered his girlfriend with a hammer and then attempted to hide the crime has now been sentenced for the coming decades.

A jury in Montgomery County deliberated for an hour and a half before finding Michael Carey Jr., 47, guilty of first-degree murder and possessing an instrument of crime in the death of 34-year-old Jessica Zipkin last November. Carey received a life sentence without the possibility of parole, which is the mandatory penalty for first-degree murder in Pennsylvania.

The crime occurred at the couple’s shared residence in Perkiomen Township on the afternoon of Nov. 1, according to the Montgomery County District Attorney’s Office. Carey is believed to have struck Zipkin over the head with a hammer more than 20 times.

However, the authorities were not informed of Zipkin’s death until after midnight on Nov. 2. Carey delayed reporting her death for ten hours, during which he allegedly attempted to conceal his actions, prosecutors stated in court, as reported by The Philadelphia Inquirer.

At around 1 a.m., Carey reportedly informed the building owner about a deceased woman in his apartment. A call to 911 was made, and responding officers discovered Zipkin lying face down on the bedroom floor with a fatal injury to the rear of her head.

Zipkin was pronounced dead at the scene, and Carey was arrested as a suspect. An autopsy conducted by the Montgomery County Coroner’s Office ruled the cause of death blunt force trauma to the head and the manner of death a homicide, PerkValleyNow reported.

Prosecutors described the death as a grisly killing.

Assistant District Attorney Christian Taffe cited a medical examiner stating Carey’s strikes with the hammer were so powerful that Zipkin’s brain was left “partially liquefied,” the Philadelphia Inquirer report adds. Prosecutors added that neighbors heard a woman’s screams in their building, and less than ten minutes later, Carey was seen entering the basement of a neighboring restaurant and discarding clothing in a trash can.

Carey took “conscious steps” to “conceal his crime,” Taffe told the Montgomery County jury.

These “steps” are said to have included showering and changing clothes in addition to the disposal of evidence. Weeks after the murder — in a recorded phone call from jail — Carey told a friend, “I heard her take her last breath … it is what it is,” investigators testified, per The Reporter newspaper.

It is unclear what set Carey off, but his defense attorneys reportedly argued he was under the control of several drugs, including methamphetamine, and thus could not have planned a premeditated attack.

“We know how these drugs can overpower you, how these drugs can overwhelm you, and that leads to a loss of being rational, and a loss of being sensible,” defense attorney Scott Frame said during the trial.

Zipkin left behind a sister, mother and father, a niece and several nephews, according to her obituary.

“You viciously killed Jessica Zipkin,” Judge Wendy Rothstein told Carey in court, according to The Reporter. “There’s no justification for that conduct. The brutality, it’s just hard to even describe.”