As investigators continued to explore an incident in which a Watsonville landowner fired a shotgun at a pickup truck he found driving on his property last week, law enforcement officials offered some advice on using guns for protection.

Bill McGrath has been trying to catch a group of thieves that have raided his Casserly Road property several times. When he saw a pickup truck driving along his driveway about 4 a.m. on Oct. 18, McGrath initially just watched, he said. However, when the truck pulled within 30 feet of the house where his children were sleeping, he went to confront the driver, he said.

Shotgun in hand, McGrath called to the driver and told him to stop and wait for sheriff's deputies to arrive, he said. When the driver drove the truck toward McGrath, he fired at the radiator and jumped out of the way.

When a deputy arrived, he scolded McGrath, McGrath said. The deputy took the shotgun while investigators determined whether McGrath committed a crime.

The incident occurred about 2:30 p.m. as Anstine prepared to board a plane for Chicago. The screeners informed airport police, who secured the weapon and detained him, said Don Marti, public safety manager at the airport.

Lincoln police cited Anstine on suspicion of carrying a concealed weapon. He was not allowed to travel as planned.

The FBI and the U.S. Attorney's Office in Omaha are conferring on whether federal charges should be filed, Johnson said.