He said the pair's methods suggested they might be the same men who had committed a number of robberies in the area over the past few months. (Para. 30)
Meaning: The officer said that the method the two robbers used in my case showed that several other robberies in the area over the past few months might be committed by those two men.
Please note "commit", a word learned in Passage B, Unit 1.
commit: vt. do sth., usually a bad thing
That fellow committed a crime when he stole the library books and sold them. 那家伙偷了图书馆的书去卖掉，这就犯了罪。
No one learned who committed the murder. 没有人知道谁是杀人凶手。