" also note that a mattress was found along the beach in the Marriot area that had Transmission fluid on it (transmission fluid is red like the color of blood)""
Hmmmmm.. Now we have transmission fluid possibly in the brother's car and also on a mattress. The car is normally kept in immaculant condition, according to the mom. Perhaps that's a link.
A car which, according to Nancy Grace, never left the driveway, so how could they have examined it?