A man who police say is the “third and final suspect” in connection to the stabbing aboard the Metro A Line in April that left a 25-year-old man dead has been arrested while trying to leave the country, according to authorities.

U.S. Customs and Border Patrol agents detained 21-year-old Compton resident Gael Cruz-Gonzalez at Los Angeles International Airport on Sunday as he was attempting to fly to Mexico, according to the Long Beach Police Department.

The agents then notified LBPD officers, who took custody of Gonzalez and transported him to jail, according to authorities.

Gonzalez faces one count of murder and one count of assault with force likely to commit great bodily injury as the charges he is facing, according to an arrest warrant that was issued for him last week. His bail was set at $2.03 million, police said.

Gonzalez, along with Akili Collins and Melake Daniel—both of whom have already been arrested and charged with murder—is responsible for the stabbing aboard the Metro A Line on the afternoon of April 12 that left 25-year-old Luis Fernando Polita dead, according to prosecutors.

Police say the trio boarded the Metro train sometime after 3:30 p.m. when it entered Long Beach, approached Polita, and assaulted him.

During the assault, one of them pulled out a knife and stabbed Polita multiple times, authorities said.

When the train came to a stop at the Metro station near First Street and Pine Avenue, Gonzalez, Collins and Daniel exited and fled on foot, authorities said.

Polita, meanwhile, was left bleeding out aboard the train until paramedics arrived and transported him to a local hospital, where he died.

Collins and Daniel were taken into custody in Long Beach a few days later and charged with murder.

Though Collins has not entered a plea, Daniel has pleaded not guilty to his charges, which also include assault with force likely to commit great bodily injury.

A motive for the attack hasn’t been made clear, although witnesses at the time said it stemmed from a previous argument aboard the train. In addition, police said Polita was specifically targeted by the suspects.

1 stabbed, 1 beaten during separate attacks along Atlantic Avenue; suspect arrested, police say