Police Officer
Policeman
noun
The police (警察) government is full of police officers. This is the formal way to say "police officer." It is similar to 警官, but has a slightly more official feel to it.
けいさつかん
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
警察官が容疑者を発見した際、男は丘の上で美しい風景画を描いていました。
When the police officer found the suspect, he was painting a beautiful landscape on a hilltop.