A St. Paul man admitted being overwhelmed with rage when he fatally shot an acquaintance in the back, sending a bullet through the victim's heart, according to charges filed Wednesday.

Lepierre C. Carpenter, 24, was scheduled to appear late Wednesday in Ramsey County District Court on a charge of second-degree murder.

Carpenter is accused of killing Parnell M. Robinson, 26, also of St. Paul, on Monday evening outside the defendant's home in the 1500 block of Ames Avenue E. Robinson's girlfriend lived in the apartment unit next to Carpenter and his girlfriend.

Carpenter was sitting on the curb when police arrived, the complaint stated. As he stood up and put his hands on his head, he said, "It's me. … I let my rage get the best of me."

According to the complaint:

Robinson's girlfriend said he saw a male friend walking nearby and yelled, "Where your fat --- going?" The friend responded that he was walking to the store, and Robinson teased that his girlfriend was making him walk to the store even though he had a car.

Shots were fired, and Robinson said "Why?" and fell to the ground. Carpenter threw the handgun in the yard, went inside and came back out to wait for police.

The dead man's girlfriend asked Carpenter why he shot Robinson. He replied, "That's what he gets for talking ---- ."

Carpenter's sister was present and told police that her brother and Robinson had been arguing on Facebook about drugs for the past few months. The sister added that Carpenter was agitated before the shooting.

She also said Carpenter had a permit to carry a firearm.

Carpenter told police he left the gun "on the step," and later asked them, "How much time do you think I'm looking at for something like this?"

But he declined to be interviewed by police and requested an attorney.

The shots that struck Robinson suggested that he ducked and turned during the shooting, according to the findings of the Ramsey County medical examiner's office.

One bullet went through his heart, and the other struck his neck and ended up at the base of his skull, the examiner's office added.