Original: Many of the Freikorps had joined the SA, so when the Night of the Long Knives came, they were among those targeted for killing or arrest, including Ehrhardt and Röhm.
Simplified: Many of the Friekorps had joined the SA, so when the Night of the Long Knives happened, they were targets for being murdered or arrested and this was also done to Ehrhardt and to Röhm.