A criminal complaint filed Monday against two Mexican nationals aboard the suspect vessel disclosed the gunshots and other measures taken by the crew to avoid getting hit early Sunday near the Channel Islands, about 180 miles northwest of the U.S.-Mexico border.

Chief Petty Officer Terrell Horne III, 34, died from head trauma after being struck by a propeller. The complaint doesn’t say which boat hit him.

Horne was assigned to the Halibut, an 87-foot patrol cutter based in Marina del Rey that was dispatched after a Coast Guard C-130 plane spotted the 30-foot “panga” vessel without lights near Santa Cruz Island, the largest of the eight Channel Islands west of Los Angeles. The panga was suspected of involvement in a drug smuggling operation.

The cutter carries a 21-foot-long, rigid-hull inflatable boat that the Coast Guard routinely uses on missions that require more speed and agility than the cutter can deliver.

Using the inflatable boat, Horne and his team came within about 20 yards of the suspect vessel at 1:20 a.m. The Coast Guard boat flashed its blue lights and the crew ordered the suspects to stop in English and Spanish before the panga gunned its engine, knocking Horne and colleague Brandon Langdon into the water, the complaint states.

Jonathan D’Arcy, one of four officers on the inflatable boat, fired several shots at the panga to avoid a collision, the complaint said. Crew member Michael Walker attempted to steer out of the way, but the panga struck the front and left side of the Coast Guard boat.

Langdon was treated for a knee injury. D’Arcy and Walker were unharmed.

Coast Guard crews followed the suspects by air and sea for nearly four hours until the vessel’s engine died 20 miles north of the Mexican border.

An officer used pepper spray on suspects Jose Meija Leyva and Manuel Beltran Higuera, who were charged with killing a federal officer while the officer was on duty.

Meija Leyva identified himself as the captain and told authorities he was taking gasoline to lost friends, according to the complaint. Beltran Higuera told authorities he was offered $3,000 to deliver gasoline to another boat that was waiting for them, but they never found it.

The complaint makes no mention of drugs being found on the boat. Coast Guard investigator Joel Widell said in an affidavit that drug or immigrant smugglers may have been using the boat to supply fuel.

Attorneys for the men did not respond to phone messages seeking comment. A judge scheduled a preliminary hearing for Dec. 17.

Horne is the first law enforcement official to die off the California coast since a spike in illegal activity began several years ago. At least six people aboard suspected smuggling vessels have been killed since the 2010 fiscal year.

In growing numbers, smugglers are turning to the California coast to bring people and drugs to the United States from Mexico. The number of Border Patrol agents on land has doubled in the past eight years, and hundreds of miles of fences and other barriers have been erected, driving smugglers to the Pacific Ocean.

U.S. authorities spotted 210 suspected smuggling vessels along California shores during the fiscal year that ended Sept. 30, up 15 percent from 183 incidents the previous year and more than quadruple the 45 incidents in 2008.

More than half the sightings were in San Diego County, which borders Mexico, but boats are turning up as far north as San Luis Obispo County on the Central Coast.

Migrants pay thousands of dollars to launch from beaches and small fishing villages south of Tijuana, Mexico. They typically use the old, single-engine wooden fishing skiffs known as pangas.

In October, a Mexican woman told authorities she agreed to pay $12,000 to be smuggled by boat into the U.S. A criminal complaint says she was among 16 people — all but one a suspected illegal immigrant from Mexico — found in a 31-foot vessel that appeared to be taking in water in the Newport Beach harbor.

In September, authorities seized 3,475 pounds of marijuana from a boat that landed near Hearst Castle on the central coast.