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

Lepierre Carpenter , 24, pleaded guilty to second-degree murder in the death of 26-year-old Parnell Robinson.

According to a press release, Carpenter apologized in court Monday but couldn’t explain his actions. He said he was under stress but didn’t intend to kill Robinson.

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 said Carpenter, who lives in the neighboring unit, fired at Robinson several times.