Conversation so far:
What were Thompson's thoughts about video games?
Thompson has heavily criticized a number of video games and campaigned against their producers and distributors.
What did he criticize about them?
His basic argument is that violent video games have repeatedly been used by teenagers as "murder simulators" to rehearse violent plans.
How well did his campaign against video games do?
Although his efforts dealing with video games have generally focused on juveniles, Thompson got involved in a case involving an adult on one occasion in 2004.
What was the 2004 case about?
This was an aggravated murder case against 29-year-old Charles McCoy, Jr., the defendant in a series of highway shootings the previous year.
How did the case end?
Although not representing McCoy and over the objections of McCoy's lawyers, Thompson succeeded in getting the court to unseal a search warrant.
What was in the search warrant?
search warrant for McCoy's residence.

Question: Why did Thompson want it unsealed?
Self-contained rewrite: Why did Thompson want the search warrant for McCoy's residence unsealed?