He would have to do this right.
There was a monster inside.
If he could, John would happily target a torpedo and blow it from existence, but he couldn't be sure if the monster's prey was dead or alive.
It was a dangerous time. Planet-wide space travel had made it easy for the monsters. It was possible to buy a ship for the same price as a house, and indeed live attached to space-stations in orbit around the Earth and The Moon. These monsters made easy work of circumventing necessary paperwork and licenses, and de-bugging their ships.
And then they were ready. They'd kidnap a child they liked and run.
Space has a lot of hiding places. Finding them is a bitch. But it's John's job to hunt them down.