Osborne and Rubio described the shooting as an "ambush." Osborne did not say how many gunshot wounds Diaz suffered, but said he was shot multiple times in the right shoulder and forearm. One bullet grazed Diaz's head.

Diaz's condition was upgraded from critical to fair early Thursday.

Harlingen Assistant Police Chief Luciano Rubio confirmed that Mexican authorities helped capture Mar on Thursday in Mexico and then transferred him to U.S. custody.

The FBI, U.S. Customs and Border Protection and Harlingen and Brownsville police departments assisted in retrieving him from Mexico, Rubio said.

Mar was being held at the Brownsville Police Department Thursday, Rubio said. Authorities planned to keep him there overnight and hold his arraignment this morning either in Harlingen or Brownsville.

Police obtained a warrant for Mar on a charge of attempted capital murder.