An 18-year-old Maryland man shot his 14-year-old half brother on a Metro train Sunday afternoon, Metro Transit Police said, but investigators don't believe the victim was the intended target.

Jermaine Brown, of Seat Pleasant, was arrested at a motel in Capitol Heights, Maryland, just before midnight after police showed surveillance images to the 14-year-old victim's parents, who told police the shooter and the victim have the same father. Brown has been charged with first-degree assault.

Police believe Brown was traveling with his half brother in a car carrying about 20 people, when he was confronted by three people between the Silver Spring and Takoma stations just before 3 p.m. Sunday.

"These three individuals square up with the shooter, some words are exchanged, the next thing you know, physical altercation occurs," Metro Transit police Chief Ron Pavlik said.

At some point, Brown pulled out a gun and fired multiple times, police said. One round hit Brown's half brother in the abdomen, and two hit the railcar, investigators said.

When the train pulled into the Takoma station, the victim collapsed on the platform, Brown fled, and the three other individuals involved got off the train, crossed to the opposite side of the platform and boarded a train in the opposite direction, police said.

They exited the system at the Silver Spring station a short time later, police said.

The victim is in stable condition, police said.

A judge ordered Brown held without bond Tuesday, saying he "presents a danger to the community and put innocent victims at risk." His next hearing is Sept. 1.

Brown, a Prince George's County, Maryland, resident and rising senior at Maya Angelou High School in D.C., got a job through the District's summer jobs program this summer, according to his attorney.

Police released photos of three persons of interest Sunday night.

Takoma update: LOOKOUT for 3 individuals considered persons of interest. Poss armed/dangerous. Call 911 or 202-962-2121 w/info. #wmata pic.twitter.com/qlQesXZIFo — Metro Transit Police (@MetroTransitPD) August 6, 2017

Anyone who sees the persons of interest should call 301-955-5000, police said.