Police in Danbury, Connecticut, are actively looking for a man who they believe fired a deadly gunshot that traveled through a wall and killed his neighbor.

Police say Victor Quispe was killed on Jan. 7 when a resident of Unit 3 of their Lake Avenue complex fired a gun and the bullet pierced the wall and struck Quispe in Unit 2, causing a fatal injury.

More learned about the suspect

Danbury police have an arrest warrant out for 42-year-old David Grullon, who they say fled the scene after the shooting.

Sources say Grullon was not supposed to possess a gun because he has a felony conviction on his record, adding he was out on bail after being charged in a 2024 assault at a bar.

Court papers say Grullon tried to intimidate the victim in that case not to press charges, warning him "We know where you live."

Attorney Gene Zingaro, who is representing Grullon on the 2024 charges, told CBS News New York that after speaking briefly with Grullon following the shooting he "hopes to help bring him back in safely."

Online campaign raises thousands of dollars for victim's family

Images online show victim Quispe living a good life. Flowers and candles continue to sit outside his Lake Avenue door.

Meanwhile, an online campaign to help Quispe's family has raised more than $80,000. His pregnant fiancée wrote, "As I grieve this unimaginable loss, I am also preparing to welcome our child into the world."

Visitation for Quispe will be Wednesday evening in Danbury. A funeral mass is scheduled for Thursday at 10:30 a.m., at St. Peter's Church in Danbury.