Police are questioning a man in his 60s over allegations that he shot and killed his son with a homemade firearm in Incheon’s Songdo area on Sunday.

According to the Incheon Yeonsu Police Station, investigators began grilling the 63-year-old man at 10 a.m. Monday after apprehending him on suspicion of murder and violating the Act on the Safety Management of Guns, Swords and Explosives.

The suspect allegedly blasted a pipe gun loaded with two rounds of buckshot containing steel pellets toward his son’s chest around 9:30 p.m. Sunday, inside the son’s home in the Songdo neighborhood of Yeonsu District.

Police say the father was visiting for a birthday party his son arranged for him, which was also attended by his daughter-in-law, his two grandchildren and acquaintances.

The son, in his 30s, was rushed to a hospital without vital signs and later pronounced dead.

The suspect allegedly fled the scene before being captured by police in Seoul around 12:20 a.m. Monday.

Police say the suspect told officers he had installed an explosive inside his own residence in Seoul’s Dobong District, after which they removed an improvised explosive device that included a timer and a flammable liquid.

They say they sent the firearm and explosive device to the National Forensic Service for analysis, while bringing in a profiler to determine the suspect’s motives and how he obtained the weapons and explosives.