Emergency services were only called for Yetunde Price after her friend, who was in violation of his parole, had driven to a house in Long Beach, at least 20 minutes away.
A spokesman for the LA sheriff’s department said yesterday that Ms Price had been seriously wounded and it was not clear whether swifter treatment would have had made any difference. He said that there are a number of trauma centres in the area the shooting took place.
A man was arrested yesterday in the Los Angeles area in connection with the murder.
Police were still seeking at least two other men as members of the Williams family arrived in LA, describing it as “the saddest day of our lives.”
Yetunde Price, 31, a nurse who worked as a personal assistant to her tennis-playing sisters, was shot dead in the early hours of Sunday morning after a row in the street in Compton, a suburb south of downtown LA, where Venus and Serena Williams grew up before moving to Florida.
Up to 20 shots were fired, according to neighbours, and Ms Price was hit in the chest.