JANESVILLE—Trial proceedings began Monday for a Fort Atkinson man charged with arson and five counts of attempted first-degree intentional homicide in connection with a fire at a Janesville duplex in 2020.

Jacob Piper, 31, is accused of throwing a Molotov cocktail at a duplex on May 28. Five people were in the building at the time of the fire and all escaped.

In his opening statement, Rock County Assistant District Attorney Jerry Urbik said the evidence would show that because of “some type of grudge” Piper endangered the lives of five people in the duplex.

Witnesses Donald Shannon and Jennifer Moffett, Urbik said, gave similar accounts regarding the incident and the events leading up to it. Based on their statements, Piper was trying to pursue a relationship with a woman in the duplex who turned him down.

Moffett told an investigator she saw Piper holding a bottle with some sort of flame coming out of it on the night of the fire. Moffett said Piper threw the bottle, causing the duplex to catch fire.

Defense attorney Mark Eisenberg objected to several of Urbik’s statements and said a mistrial should be declared because Urbik’s opening remarks. Judge Karl Hanson said those objections would be addressed in court Tuesday.

Eisenberg argued Piper did not thow the firebomb into the duplex. He said the prosecution’s case relied on witness testimony that were not consistent.

Eisenberg said both Moffett and Shannon gave conflicting stories and regularly changed details regarding where Piper was before the fire. Eisenberg tried to cast further doubt on Moffett’s story, claiming she could not have seen Piper from her bedroom window.

Eisenberg also said there were several flammable items on the porch when the fire broke out after a cookout at the residence the night of May 27.

After the opening statements, Urbik called the prosecution’s first witness, who saw the fire from his house on River Street. Christopher Colby said he had gotten up and was using the restroom when he heard a booming sound from down the street. When he looked to see what caused the noise, he said he saw the porch and front door of the Franklin Street duplex on fire.

Colby described the fire as “rolling” down the wooden stairs “like water,” then crawling up the building to the second floor. He said he called 911 .

Heidi Fairman, Colby’s mother, was next on the stand and gave a statement similar to her son’s. She too had been startled by the booming sound from down the street and saw the fire immediately, then saw people jumping from the balcony shortly thereafter.

The trial will resume at 8:30 a.m. Tuesday, when more evidence is set to be presented and further testimony will be heard.