Answer: Interview, via reliance on available subjects, citizens that are in the park
Explanation: In other to determine the level of fear construct in the park, that if it has reduced, worsened or has no effect on the rate of crime in the park due to the installation of a closed circuit television. The best way to ascertain the impact of the closed circuit television on people's fear of committing crime is by engaging trusted individuals in the park, they could be those who visit the park regularly or those who trade their goods there, to get reliable update on the rate of crime since the CCTV installation.