A Louisiana high school student was fatally shot near a bus stop Monday, prompting deputies to detain four young people.

Jefferson Parish Sheriff Joseph Lopinto said investigators didn’t know a motive, or whether the shooting was random or the result of mistaken identity, news outlets reported.

“I spoke with relatives and every indication from the people I’ve talked to was that this was a very good kid,” he said during a news conference. “We’re not getting any indication from speaking with community or family that he was a troubled kid.”

The victim, whose name was not immediately released, was shot about 7:30 a.m. He was a student at John Ehret High School in Marrero, across the Mississippi River from most of Jefferson Parish and neighboring New Orleans.

Lopinto said three males and a female were being questioned. He declined to call them suspects.

He said deputies ran after three people who got into a vehicle which drove off. Other deputies stopped a vehicle that matched its description.

Investigators saw a rifle but were waiting for a search warrant to check it out, the sheriff said.

Jefferson Parish Public Schools sent crisis teams to the high school, Superintendent James Gray said.