"犯盗窃罪的" can be translated into English as "those who commit theft" or "those guilty of theft".
If you want a more concise phrase that could be used as an adjective or in a descriptive context, you might say "theft-committing" (though this is less common in everyday English) or simply refer to them as "thieves" (if referring to the general category of people who commit theft). However, "those who commit theft" or "those guilty of theft" more accurately capture the meaning of "犯盗窃罪的" in a legal or descriptive context.