$ curl https://raw.githubusercontent.com/washingtonpost/data-homici... | grep 'Closed by arrest' | wc -l

25667

$ curl https://raw.githubusercontent.com/washingtonpost/data-homici... | grep -v 'Closed by arrest' | wc -l

26506

Wow that's depressing. All possible outcomes via

$ curl https://raw.githubusercontent.com/washingtonpost/data-homici... | cut -f 12 -d ',' | sort | uniq -c

          1 Closed by arrest
      25673 Closed by arrest
       2922 Closed without arrest
          1 disposition
      23583 Open/No arrest

Pretty sure that 'Closed by arrest' also regularly results in a 'Not guilty' down the pipeline, so the 'real' number is probably much lower.