High-spin states up to ( -+) and ( -) in As have been studied via the Ni(' F,n2p) reaction at 62 MeV using in-beam p-ray spectroscopic techniques. Based on a particle-p coincidence measurement a new decay sequence of negative parity has been assigned to As. Lifetimes for some E2 transitions were extracted from Doppler-shifted line shapes observed in coincidence mode, and experimental transition quadrupole moments were determined. They indicate a moderate to high collectivity in both the positive-parity yrast band and the new negative-parity decay sequence at high spins. Total Routhian surfaces calculated for states of both parities reveal strong triaxial shapes at high spins. A noncollective structure of '~and~states is interpreted as a three-quasiparticle excitation.PACS number(s): 21.10. Tg, 23.20.Lv, 27.50.+e