More details emerged about Austin men charged with planning an attack at the Republican National Convention.

Police say David McKay and Bradley Crowder planned to attack police near the convention with homemade explosives.

A confidential source working with the FBI was traveling with the men.

On Wednesday, when police searched the apartment where the group was staying, they found gas masks, bolt cutters and eight fully-assembled Molotov cocktails.

Prosecutors say McKay and Crowder are part of a local group called "Austin Affinity" and the FBI has been watching that group since early last year.

According to the arrest affidavit for McKay and Crowder, the two left Austin on August 28th along with 6 group members in a rented van and trailer.

In it were 35 shields made from stolen construction barrels.

The source told the FBI the group had plans to protest and somehow disrupt the Republican National Convention.

On August 31st, Crowder, McKay, and members of the Austin Affinity group went to a St. Paul Wal-Mart and purchased items including gasoline, tampons, motor oil, and bolt cutters.

On September 1st, McKay was arrested, cited, and released by St. Paul police for disorderly conduct outside of the RNC.

On September 2nd, the FBI listened in on a conversation between McKay and a confidential source.

McKay told the source he and Crowder had made several Molotov cocktails and planned to light and throw them at vehicles in a parking lot near the convention that was being used by police and secret service. According to that source, the man asked McKay, "What if there's a cop sleeping in the car?

McKay replied, "It's worth it if an officer gets burned or maimed."

David McKay and Bradley Crowder are in FBI custody in Minnesota tonight.

They both face federal charges for possession of fire arms.

If convicted, they could get a maximum of 10 years in prison.