A Pennsylvania man is facing trial, accused of fatally shooting his former girlfriend just moments after she ended their relationship. Authorities claim he used the intervening time to look up instructions on firing a gun.

Michael Dutkiewicz, 26, has been charged with first-degree murder, third-degree murder, and possession of a criminal instrument in connection with the death of 25-year-old Alyssa Wiest. Although the incident occurred in May, the courtroom in Montgomery County has recently been packed as prosecutors revealed more details about the tragic event.

According to prosecutors, Dutkiewicz and Wiest had been in a relationship for two years and were out at a bar on the evening of May 17, as reported by Philadelphia’s Fox affiliate WTXF. Upon returning home, Wiest dropped a bombshell: she wanted to end the relationship.

Wiest’s older sister noted that Wiest had contemplated the breakup since March but postponed her decision until after a trip funded by Dutkiewicz’s family, according to local reports.

After the breakup, Dutkiewicz allegedly turned to the internet to learn how to load and operate a revolver. Just after midnight, he is accused of putting this newfound information into action.

West Conshohocken police officers reported being called to a residence on the 200 block of Moorehead Avenue at about 12:25 a.m. on May 18. When they arrived, they found “a female, later identified as Alyssa Wiest, face down on the sidewalk, with obvious gunshot wounds to her torso,” the Montgomery County District Attorney’s Office said.

She was brought to a nearby hospital, where she was pronounced dead. Dutkiewicz is alleged to have shot and killed her just 25 minutes or so after she broke up with him — using the victim’s own personal revolver, prosecutors say.

Detectives launched a homicide investigation, and prosecutors said they found several pieces of evidence. For one, the door to Wiest’s home, “a few doors from where she was found, was ajar, and there was blood found both inside her residence and along the sidewalk leading to her body.” Five “projectiles” were also recovered, both inside the home and outside by her body.

In court this week, neighbors reportedly described the gunshots and Wiest’s screams as she ran down the sidewalk in an apparent attempt to get away from her attacker.

Investigators said that “immediately after the shooting, a neighbor saw Dutkiewicz standing by his silver Ford F-150 truck” — and then the truck left the area. License plate readers confirmed that a truck belonging to Dutkiewicz was driving from West Conshohocken and through Conshohocken at 12:25 a.m. that night, authorities said.

A warrant was later issued for his arrest, and he turned himself in. He was placed in the Montgomery County Correctional Facility.

Dutkiewicz’s defense team is not disputing who committed the killing, but rather arguing that the attack was caused by a sudden emotional moment and not premeditated, according to WTXF. Video evidence is expected as the trial continues, and a jury could deliberate as soon as Thursday.

Wiest’s obituary describes her as “our beloved shining star—radiant, vibrant, and full of light. Her presence lit up every room she entered, and her absence leaves a deep ache in the hearts of all who knew and loved her.”