autopsy: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/autopsy - from package: autopsy

You may install the required package with command apt-get install {package}
Error in other languages:
autopsy: bevel nie gevind nie
autopsy: comandă negăsită
autopsy: comando não encontrado
autopsy: commande introuvable
autopsy: command not found
autopsy: käsku ei ole
autopsy: không tìm thấy lệnh
autopsy: komanda nerasta
autopsy: Kommando nicht gefunden.
autopsy: kommandot finns inte
autopsy: komut yok
autopsy: nie znaleziono polecenia
autopsy: níor aimsíodh an t-ordú
autopsy: no se encontró la orden
autopsy: no s'ha trobat l'ordre
autopsy: opdracht niet gevonden
autopsy: parancs nem található
autopsy: perintah tidak ditemukan
autopsy: príkaz nenájdený
autopsy: příkaz nenalezen
autopsy: команда не найдена
autopsy: командата не е открита
autopsy: 命令找不到
autopsy: コマンドが見つかりません