The police took the suspect into custody.
The suspect has the right to remain silent.
The police arrested the man as a suspect.
The detective is interrogating the suspect.
The prosecutor's office took the suspect into custody.
The suspect confessed to the incident.
容疑者 is the common word for 'suspect' used in news and everyday speech, while 被疑者 is the stricter legal term used in criminal procedure documents.
被疑者 is the person suspected of committing a crime, while 被害者 is the person who suffered from it.
被疑者 refers to someone merely suspected of a crime and not yet proven guilty, whereas 犯人 means the actual perpetrator who committed the crime.
容疑 refers to the suspicion itself, while 被疑者 refers to the person who is suspected.
Compound of 被 (ひ, 'receive, incur') + 疑 (ぎ, 'doubt, suspicion') + 者 (しゃ, 'person'). The exact historical derivation is uncertain, but the kanji combination transparently means 'person under suspicion'.