Tuhia he tomokanga mō tēnei wāhanga - I te 2012 Summer Olympics i Rānana, i whakataetae a Halsall i roto i ngā kaupapa e rima. Kua eke a Halsall ki te whiringa toa o te 100m butterfly
I tukuna e ia he wa o 58.52, he pai ake i tana wa pai o 57.56 i whakaturia i te marama o Poutu-te-rangi. I eke a Halsall ki te whiringa toa o te 100m freestyle me te 50m freestyle, ka mutu te 6 me te 5 o nga wa. I roto i te 4 × 100 m freestyle relay Halsall i kaukau i te waewae tuarua i roto i te wehenga o te 53.29, ka awhina i te roopu o Ingarangi ki te whakaoti i te 5 o nga waahi. I te whakamutunga o te 4 × 100 m medley relay i mutu te kapa o Ingarangi i te 8th, me Halsall e whakarato ana i te waewae pungawerewere o 54.08.