A 19-year-old south Minneapolis man has been charged with stabbing his neighbor to death during a confrontation outside their apartment building, authorities said, although a clear picture of what prompted the attack has yet to emerge.

Prosecutors said that Robinson Fabricio Palacios-Castro, who was arrested the day before Thanksgiving at an apartment building in the 3200 block of S. Clinton Avenue, was charged Monday with the murder of his upstairs neighbor, 29-year-old Elias Benjamin Lopez Lopez.

Lopez was found lying facedown on the front steps of the building about 11:19 p.m. with multiple stab wounds, police said. He was rushed by ambulance to Hennepin County Medical Center, where he went into surgery, but later died, according to the complaint.

According to a criminal complaint, Palacios-Castro was arrested after returning to his basement apartment about two hours after the stabbing occurred. When officers questioned him, he initially denied any involvement in the incident, but after police found a kitchen knife in his waistband, he told them that he used the knife to defend himself from being attacked by three men who jumped him outside of the building, the complaint read.

But another neighbor told responding officers that he was pulling into the parking lot when he saw the two men fighting, both of whom he recognized from the building, police said. Police said the neighbor ran inside to call 911 and when he came back out, he saw Palacios-Castro stabbing Lopez. When the neighbor yelled at Palacios-Castro to stop, the suspect allegedly turned on him, chasing the man for several blocks before fleeing the scene.

The complaint did not give a reason for the attack. Palacios-Castro remains in the Hennepin County Jail in lieu of $1 million bail.

Last week, friends and relatives remembered Lopez, a Guatemalan national who worked at several restaurants in St. Paul’s Cathedral Hill neighborhood, as a hardworking man who loved his family, fishing and who dreamed of someday going back to college.

A family friend set up a GoFundMe page to raise money to fly Lopez back to Guatemala and to cover funeral costs.