The authors show how photoelectron angular distribution ( beta parameter) measurements in cadmium reveal the existence of an autoionizing level that cannot be seen in the photoabsorption spectrum. Ab initio 5p6s configuration parameters are used in a new calculation of beta in the 4d⁹5s²5p ³P₁ resonance region. Good agreement between theory and experiment enables the assignment of 5p6s ³P₁ and ¹P₁.