A man suspected in a New Year’s Eve party shooting was caught at the U.S.-Mexico border Sunday night trying to come back into the United States, Watsonville police reported.

Jose Vargas, a 21-year-old from Salinas, was arrested at the Winterhaven port-of-entry, in eastern California near Andrade, on suspicion of attmpted murder, according to Watsonville police detective Morgan Chappell.

“I got the arrest warrant and I flagged the border because I was afraid he was going to run to Mexico,” said Chappell, a gang investigator assigned to the shooting case. “We knew he had ties to Mexico so we were just covering all possible angles of escape.”

Border Patrol was notified Jan. 5, police said.

In fact, Vargas had already been to Mexico and was on his way back the U.S. when he was caught. He has been detained by the Border Patrol and will be brought back to Santa Cruz County later this week, according to police.

Chappell said Vargas is suspected of shooting a 24-year-old Watsonville man in the torso at a house party on Southern Circle just before midnight on New Years.

It took some legwork by police detectives to identify Vargas as the gunman. Chappell said Vargas was driven from the party by his girlfriend, 20-year-old Margarita Ruiz Lara of Watsonville. Police arrested her Jan. 3 on suspicion of being an accessory to a crime and reportedly found pictures of Vargas in her room. From there, witnesses allegedly confirmed Vargas was the party shooter, Chappell said.

Neither Vargas nor Lara had been invited to the party by the hosts, but another partygoer who is friends with Lara told her to come over. Somehow, things went sideways minutes before midnight.

“It was just a couple of minutes before midnight,” Chappell said. “From witnesses and people who saw the shooting happen, it seemed to be an unprovoked shooting.”

Chappell said the motive is still unclear.

“We’re still investigating that,” he said. “What we can say is the shooting is gang related.”

Vargas hasn't been in trouble in Watsonville in the past, save one ticket for driving without a license.

Lara is free on bail, who also has been identified as Margarita Ruiz by police. The victim is recovering.

“He’s doing well,” Chappell said. “He’s going to survive.”