The father of the gunman who was killed after shooting at Border Patrol agents in McAllen warned police that his son was known to have an AR-15 and a pistol with him, according to an incident report obtained by Channel 5 News.

Ryan Louis Mosqueda of Michigan died on Monday after authorities said he arrived to the Rio Grande Valley Border Patrol Annex in McAllen and shot at the building and the agents in it.

Mosqueda, 27, was armed with an assault style rifle and tactical gear in the shooting that injured three people.

Federal agents returned fire, killing Mosqueda.

READ MORE: Gunman dead after opening fire at McAllen Border Patrol facility

According to McAllen Police Chief Victor Rodriguez, Mosqueda had been reported missing in Weslaco prior to the shooting.

The incident report from the Weslaco Police Department shows that Mosqueda’s father —Jose Mosqueda — reported that his son was missing at around 3:48 a.m. Monday.

According to the report, Jose was pulled over in Weslaco and told a police officer he was searching for his son, who he had not seen since 2:30 a.m.

According to Jose, he had told Mosqueda to go to bed since they would be leaving to Michigan in the morning, but they got into an argument over a Chevrolet Cobalt Mosqueda wanted to take with him. Jose told him to wait until December when they returned.

Mosqueda was “upset” following the argument, and Jose went to take a shower. He later noticed his son had left in the Cobalt.

While talking to police, Jose said Mosqueda is “known to have a AR-15 and pistol inside of his truck,” the report said.

The report added that Mosqueda may also have had a handgun in the trunk.

READ ALSO: FBI activity in Weslaco linked to deadly Border Patrol shooting investigation

As previously reported, a spokesperson for the Weslaco Police Department said that Jose told police that his son had "mental deficiencies," but there was no documentation available to support that.

At 5:53 a.m., “30-60” shots were heard coming from the Border Patrol facility in McAllen. 

By 5:59 a.m., responding officers reported that the shooter, identified as Mosqueda, was down.

A motive is not yet known in the shooting. The FBI is investigating the incident.