Spain, Catalan Parliament holds investiture session of Socialist Party candidate Salvador Illia
*Former president of Catalonia Carles Puigdemont returned from exile after almost seven years
*Carles Puigdemont could be arrested
*Thousands of supporters rallied in support of Puigdemont
*Carles Puigdemont could be arrested
*Thousands of supporters rallied in support of Puigdemont