 Richard Grieco , known for his role as Dennis Booker on the original 21 Jump Street TV series , appears for the first time as Steve <unk> , Mindy O 'Dell 's ex @-@ husband . In 2012 , the New York Daily News called Grieco 's role on Veronica Mars " his last mainstream role " . Ryan <unk> guest stars as Danny <unk> , a <unk> shop employee . He would go on to make a guest appearance on series creator Rob Thomas 's later show Party Down . Robert <unk> <unk> appears as Mason , Wallace 's friend . 
