ST. PAUL — A St. Paul man says he can’t explain why he shot and killed his neighbor this summer.

Twenty-four-year-old Lepierre Carpenter pleaded guilty to second-degree murder in the death of 26-year-old Parnell Robinson.

The St. Paul Pioneer Press reports Carpenter apologized in court Monday but couldn’t explain his actions. He says he was under stress but didn’t intend to kill Robinson.

The shooting happened Aug. 3 at a public housing complex in St. Paul.

Robinson was on the front porch with his girlfriend and the woman’s 3-year-old daughter, when Robinson saw a friend and teased him about walking to the store. The complaint says Carpenter, who lives in the neighboring unit, fired at Robinson several times.

Sentencing is set Jan. 15. Carpenter is expected to receive 25 years in prison.