Supergirl: Death & the Family #1

Supergirl secretly subdues a gang of bank robbers, but anti-Kryptonian paranoia causes the Science Police Squad K to detain all the hostages and use Red Kryptonite to find out which of them used super-powers. Supergirl, as Linda, evades detection, but another woman and her son are outed as Kryptonians, which ruins their lives.