The driver of a Jeep that sped through a fire barricade in West Hollywood, striking a Los Angeles County fire captain, was identified as David Allan Gilbert, 24, of Hollywood. Capt. Glen Johnson was not hurt seriously, but a sheriff's spokesman said Gilbert was booked on suspicion of attempted murder. The barricade had been set up to control traffic as firefighters worked a blaze at a furniture warehouse in the 8700 block of Santa Monica Boulevard that caused more than $750,000 damage. About two hours later, another fire broke out in the 8400 block of the boulevard, causing about $100,000 in damage to cars and some equipment belonging to the Cousteau Society. Both blazes were under investigation for possible arson.