An 11-year-old boy in St. Louis County, Mo., fatally shot a 16-year-old who police believe was attempting a home invasion, but neighbors of the younger boy say what happened Thursday afternoon was not a break-in.

Police told the Associated Press that two suspected burglars, the 16-year-old shooting victim and a 22-year-old who is now in custody, tried multiple times to break into the home, and made it through the front door on their third attempt. The teen was apparently gunned down in the foyer.

The 11-year-old was home alone with his four-year-old sister at the time. Their mother said she’d purchased the gun for protection after previous home invasion attempts.

But neighbors say there’s no way there was a break-in in the middle of the day. One, Donna Jackson, says she saw a conversation between the two boys, then a point-blank shooting.

“It was not a break-in,” Jackson told the St. Louis Post-Dispatch, “He shot him in the head.”

Another neighbor said the teen was trying to sell the 11-year-old a phone, but when the older boy reached the house, the younger one shot him.

“He was never in the house,” Jazmyne Clark told the Post-Dispatch, “He wasn’t breaking in at all. He was just trying to sell him his phone.”

She added the 11-year-old had been waving a gun around in front of the house earlier in the day.

A third neighbor said the shooter was a known troublemaker who had previously broken into her house and stolen cell phones.

Police told the Post-Dispatch they’re sticking to the home invasion account for now, but they’re not done interviewing witnesses, and they want anyone with information to come forward.

[Big Story, Photo: KMOV via CNN]