Welcome to the forum, and sorry for your loss.
Junipers can turn brown for many reasons, and the sad news is they usually don't show the browning until it's too late to do anything; think Xmas trees, keeping green during November, December, and then turning suddenly brown and dying; in fact they were already dead in December, but just not showing it.
On a brighter note, keep it outside at all times, water it when the soil feels dry (they don't like wet feet), give it a little fertilizer, and let's hope for the best.
The soil it is planted in looks very organic and wet, they usually like fast inorganic draining soil best.
Good luck!